I've just noticed that the long, convoluted Facebook URLs that we're used to now look like this:
http://www.facebook.com/example.profile#!/pages/Another-Page/123456789012345
As far as I can recall, earlier this year it was just a normal URL-fragment-like string (starting with #), without the exclamation mark. But now it's a shebang or hashbang (#!), which I've previously only seen in shell scripts and Perl scripts.
The new Twitter URLs now also feature the #! symbols. A Twitter profile URL, for example, now looks like this:
http://twitter.com/#!/BoltClock
Does #! now play some special role in URLs, like for a certain Ajax framework or something since the new Facebook and Twitter interfaces are now largely Ajaxified?
Would using this in my URLs benefit my Web application in any way?
This technique is now deprecated.
This used to tell Google how to index the page.
https://developers.google.com/webmasters/ajax-crawling/
This technique has mostly been supplanted by the ability to use the JavaScript History API that was introduced alongside HTML5. For a URL like www.example.com/ajax.html#!key=value, Google will check the URL www.example.com/ajax.html?_escaped_fragment_=key=value to fetch a non-AJAX version of the contents.
The octothorpe/number-sign/hashmark has a special significance in an URL, it normally identifies the name of a section of a document. The precise term is that the text following the hash is the anchor portion of an URL. If you use Wikipedia, you will see that most pages have a table of contents and you can jump to sections within the document with an anchor, such as:
https://en.wikipedia.org/wiki/Alan_Turing#Early_computers_and_the_Turing_test
https://en.wikipedia.org/wiki/Alan_Turing identifies the page and Early_computers_and_the_Turing_test is the anchor. The reason that Facebook and other Javascript-driven applications (like my own Wood & Stones) use anchors is that they want to make pages bookmarkable (as suggested by a comment on that answer) or support the back button without reloading the entire page from the server.
In order to support bookmarking and the back button, you need to change the URL. However, if you change the page portion (with something like window.location = 'http://raganwald.com';) to a different URL or without specifying an anchor, the browser will load the entire page from the URL. Try this in Firebug or Safari's Javascript console. Load http://minimal-github.gilesb.com/raganwald. Now in the Javascript console, type:
window.location = 'http://minimal-github.gilesb.com/raganwald';
You will see the page refresh from the server. Now type:
window.location = 'http://minimal-github.gilesb.com/raganwald#try_this';
Aha! No page refresh! Type:
window.location = 'http://minimal-github.gilesb.com/raganwald#and_this';
Still no refresh. Use the back button to see that these URLs are in the browser history. The browser notices that we are on the same page but just changing the anchor, so it doesn't reload. Thanks to this behaviour, we can have a single Javascript application that appears to the browser to be on one 'page' but to have many bookmarkable sections that respect the back button. The application must change the anchor when a user enters different 'states', and likewise if a user uses the back button or a bookmark or a link to load the application with an anchor included, the application must restore the appropriate state.
So there you have it: Anchors provide Javascript programmers with a mechanism for making bookmarkable, indexable, and back-button-friendly applications. This technique has a name: It is a Single Page Interface.
p.s. There is a fourth benefit to this technique: Loading page content through AJAX and then injecting it into the current DOM can be much faster than loading a new page. In addition to the speed increase, further tricks like loading certain portions in the background can be performed under the programmer's control.
p.p.s. Given all of that, the 'bang' or exclamation mark is a further hint to Google's web crawler that the exact same page can be loaded from the server at a slightly different URL. See Ajax Crawling. Another technique is to make each link point to a server-accessible URL and then use unobtrusive Javascript to change it into an SPI with an anchor.
Here's the key link again: The Single Page Interface Manifesto
First of all: I'm the author of the The Single Page Interface Manifesto cited by raganwald
As raganwald has explained very well, the most important aspect of the Single Page Interface (SPI) approach used in FaceBook and Twitter is the use of hash # in URLs
The character ! is added only for Google purposes, this notation is a Google "standard" for crawling web sites intensive on AJAX (in the extreme Single Page Interface web sites). When Google's crawler finds an URL with #! it knows that an alternative conventional URL exists providing the same page "state" but in this case on load time.
In spite of #! combination is very interesting for SEO, is only supported by Google (as far I know), with some JavaScript tricks you can build SPI web sites SEO compatible for any web crawler (Yahoo, Bing...).
The SPI Manifesto and demos do not use Google's format of ! in hashes, this notation could be easily added and SPI crawling could be even easier (UPDATE: now ! notation is used and remains compatible with other search engines).
Take a look to this tutorial, is an example of a simple ItsNat SPI site but you can pick some ideas for other frameworks, this example is SEO compatible for any web crawler.
The hard problem is to generate any (or selected) "AJAX page state" as plain HTML for SEO, in ItsNat is very easy and automatic, the same site is in the same time SPI or page based for SEO (or when JavaScript is disabled for accessibility). With other web frameworks you can ever follow the double site approach, one site is SPI based and another page based for SEO, for instance Twitter uses this "double site" technique.
I would be very careful if you are considering adopting this hashbang convention.
Once you hashbang, you can’t go back. This is probably the stickiest issue. Ben’s post put forward the point that when pushState is more widely adopted then we can leave hashbangs behind and return to traditional URLs. Well, fact is, you can’t. Earlier I stated that URLs are forever, they get indexed and archived and generally kept around. To add to that, cool URLs don’t change. We don’t want to disconnect ourselves from all the valuable links to our content. If you’ve implemented hashbang URLs at any point then want to change them without breaking links the only way you can do it is by running some JavaScript on the root document of your domain. Forever. It’s in no way temporary, you are stuck with it.
You really want to use pushState instead of hashbangs, because making your URLs ugly and possibly broken -- forever -- is a colossal and permanent downside to hashbangs.
To have a good follow-up about all this, Twitter - one of the pioneers of hashbang URL's and single-page-interface - admitted that the hashbang system was slow in the long run and that they have actually started reversing the decision and returning to old-school links.
Article about this is here.
I always assumed the ! just indicated that the hash fragment that followed corresponded to a URL, with ! taking the place of the site root or domain. It could be anything, in theory, but it seems the Google AJAX Crawling API likes it this way.
The hash, of course, just indicates that no real page reload is occurring, so yes, it’s for AJAX purposes. Edit: Raganwald does a lovely job explaining this in more detail.
How to prevent downloading images and video files from my website? Is it possible?
What would be the best way to do this?
No, it's not possible.
If you can see it, you can get it.
Don't post them to your site.
Otherwise it is not possible.
As the browser needs to transfer the content to display it (text, images, videos), the data is already on the client's computer when the website is displayed. The previous answers give little advice on how to make it harder for non-experienced users to grab the content. Here are some directions:
General
Overlay the respecitive contents with a transparent <DIV> or a
transparent image (as described in some answers to this question)
Open the website in a frameset, so saving may miss the frame content.
Open the website via window.open() to hide the menu bar.
Disable right-clicks via JavaScript (not recommended due to all the side-effects on usability)
Load the page's HTML code from another file (which may check for a specific referer or which may be ROT13) via JavaScript, so it's harder to access the source code.
Tell the browser that all content is display:none for the printer (something like #media print { body, div, p { display: none } })
Use JavaScript to hide the content before a client makes a screenshot (see Stop User from using “Print Scrn”)
Try to disable or overwrite the clipboard (see this post)
Images
Do not use the <img> tag for images but set the image as background for a <DIV>
Wrap images into SVGs or Flash movies to make them very hard to access in a usable format.
Disable caching for images (via <meta> tag or by setting the appropriate header on server delivery), so they are not stored in the browser cache (immeaditely accessible on the client's computer).
Cut an image into parts, so it takes some extra work to reconstruct the whole image
Add onmousedown events to images, e.g., display a copyright alert.
Deliver the image via server script (e.g., PHP) and check the referer.
Videos
Stream videos to prevent simple downloading via URL.
Wrap videos into a Flash movie.
Use some nasty format that supports DRM.
Texts
Make text unselectable (see How to make HTML Text unselectable)
Additionally to overlaying, wrap the text into JavaScript (e.g., after ROT13 or loaded dynamically from a second file), so the text is not directly available in the source code.
Convert texts to images (this may decrease display quality), SVGs or Flash
Again, I repeat that none of this will stop an experienced user from grabbing the content (e.g. by making a screenshot and - optionally - run OCR on it). Sometimes it's as easy as using the browser's developer tools or using the website without JavaScript. Yet, it will give inexperiences users a hard time, so they may look for some easier source to grab from.
Also keep in mind that the above techniques will affect search engines when reading the page's content (if you're interested in blocking them, start with a robots.txt).
Thank you for any other ideas to complement the above list!
Images must be downloaded in order to be viewed by the client. Videos are a similar case, in many scenarios. You can setup proxy scripts to serve the files out, but that doesn't really solve the issue of preventing the user from getting their own copy. For a more thorough discussion of this topic, see the question How can I prevent/make it hard to download my flash video?
If you are using PHP, the best way is to control it the .htaccess, you need to put your files, images and videos under consideration in a separate folder/directory, and create a new .htaccess file in this directory with the below:
RewriteEngine On
RewriteCond %{REQUEST_URI} \.(mp4|mp3|avi)$ [NC]
RewriteCond %{HTTP_REFERER} !^http://sample.com/.*$ [NC]
RewriteRule ^.* - [F,L]
The first line %{REQUEST_URI} will prevent getting the file through the web browser or through curl.
The second line %{HTTP_REFERER} will prevent accessing the image/video using HTML tags <img> or <video> from any website except the exception ! you provide instead of http://sample.com/ which usually should be your website itself.
You can also have a look at my question and the accepted answer here for more tricks on the browser side.
I'd like to add a more philosophical comment. The whole intent of the internet, particularly the World Wide Web, is to share data. If you don't want people to download a picture/video/document, don't put it on the web. It's really that simple. Too many people think they can impose their own rules on an existing design. Those who want to post content on the web, and control its distribution, are looking to have their cake and eat it too.
In short, no. If someone can view an image or video in their browser then they have, by definition, downloaded it. That's how the web works - it is client server based. Whatever you can view in your browser (client) has been transfered to your computer from the remote website (server).
In standard HTML, I don't know of anyway.
You didn't really say, but I'm guessing you are having problems with people deep linking into your content. If that's the case, and you are open to server side code, I believe this might work:
Create a page that accepts a numeric
id, maps it to a server file path,
opens that file, writes the binary
directly to the response stream.
On the page request, generate a
bunch of random ids, and map them to
the actual media urls, and store that
mapping object server side somewhere
(in session?) with a limited life.
Render your pages with your media
links pointing to the new media page
with the appropriate id as a query
string argument.
Clear the mapping object and generate
all new links on every postback.
This :
won't stop people from downloading
from within your page
definitely isn't as lightweight as standard
HTML
and has it's own set of issues.
But it's a general outline of a workable process which might help you prevent users from deep linking.
As many have said, you can't stop someone from downloading content. You just can't.
But you can make it harder.
You can overlay images with a transparent div, which will prevent people from right clicking on them (or, setting the background of a div to the image will have the same effect).
If you're worried about cross-linking (ie, other people linking to your images, you can check the HTTP referrer and redirect requests which come from a domain which isn't yours to "something else".
you can reduce the possibility but not eliminate it...
It also doesn't hurt to watermark your images with Photoshop or even in Lightroom 3 now. Make sure the watermark is clear and in a conspicuous place on your image. That way if it's downloaded, at least you get the advertising!
This is how I do it in case anyone in the future is wondering.
I put this in the .htaccess file on the root server:
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com/ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com.*$ [NC]
RewriteRule \.(mp4|avi)$ - [F]
This stops them from say going to domain.com/videos/myVid.mp4 and then saving it from there.
No it's not. You may block right-clicks and simillar stuff but if someone wants to download it, he will do so, trust me ;)
As soon as they view your page that includes the picture or video, the item is downloaded into the temporary folder of their browser. So if you don't want it downloaded, don't post it.
You can mark folders or files so that they don't have read access (any of the main web servers support this). This allows you to store them on the server without any level of access to the outside world. You may want to do this if you have a service that generates images for someone else to download later, or if you use your web account for FTP access, but don't want anyone to view the files. (i.e. upload a .bak file to the server for someone else to FTP down again).
However, as others have said, getting into copyright areas where people can view the image or video but not save them locally is not fully possibly, although there are tools to discourage illegal usage.
Put your image or video in flash format. Works great.
This is an old post, but for video you might want to consider using MPEG-DASH to obfuscate your files. Plus, it will provide a better streaming experience for your users without the need for a separate streaming server. More info in this post:
How to disable video/audio downloading in web pages?
I believe THEOplayer already provides this sort of solution as a paid service, but I'm not so sure about it.
Granted that any image the user can see will be able to be saved on the computer and there is nothing you can do about it. Now if you want to block access to other images that the user is not supposed to see, I am actually doing it that way:
Every link is to the "src" in your image tag is in fact a request
send to a controller on the server,
the server checks the access
rights of that specific user, and returns the image if the user is
supposed to have access to it,
all images are stored in a directory
that is not directly accessible from the browser.
Benefit:
The user will not have access to anything that you don't intent him/her to have access to
Drawback:
Those requests are slow.. especially is there are lots of images on the same page. I haven't found a good way to accelerate that in fact..
You can set the image to be background image and have a transparent foreground image.
I think the best way is:
STREAM THE VIDEO IN SEPARATED ENCRYPTED PARTS.
There are video hosting services such as vzaar that have this functionality.
As far as I know, that will make it really hard to download directly. At least for 95% of the people.
But of course, if the video plays on the screen people can just use a screen recorder and some simple software to record sound from the audio output (but he/she will have to play the ENTIRE thing to save it, totally inconvenient).
You can't stop image/video theft but you can make harder for normal users but you can't make it harder for the programmers like us (I mean thieves that know little web programming).
There are some tricks you can try:
1.) Using flash as YouTube and many others sites like http://www.funnenjoy.com does.
2.) Div overlaping or background pic setting (but users with little sense can easily save all resources by opening inspect element or other developer option).
3.) You can disable right click and specific keys like CTRL + S and others possibles with JavaScript but main drawback is that if user disable JavaScript our all tricks fail down.
4.) Save image in none online directories (if you have full access to web server) and read that files with server side languages like PHP every time when image / video is required and change image id time to time or create script that can automatically change ID after every access.
5.) Use .htaccess in apache to prevent linking of your images by others sites. you can use this site to automatically generate .htacess http://www.htaccesstools.com/hotlink-protection/
Insert a transparent gif 1px x 1px just inside the <body> tag:
<body><img src="route-to-images/blim.gif" class="blimover">
Then style it with this:
.blimover {
width: 100% !important;
height: 100% !important;
z-index: 1000 !important;
position: absolute !important;
top: 0 !important;
left: 0 !important;
}
This will remove any click functionality from a page, but it sure stops people stealing any content!
You can apply the same to a <div>, <section>, <article> etc, just name accordingly and prevent your copy and/or images being ripped.
Nothing stops a screengrab though ... ...
If you want only authorised users to get the content, both the client and the server need to use encryption.
For video and audio, a good solution is Azure Media Services, which has content protection and encryption. You embed the Azure media player in your browser and it streams the video from Azure.
For documents and email, you can look at Azure Rights Management, which uses a special client. It doesn't currently work in ordinary web browsers, unfortunately, except for one-off, single-use codes.
I'm not sure exactly how secure all this is, however. As others have pointed out, from a security point of view, once those downloaded bytes are in the "attacker's" RAM, they're as good as gone. No solution is 100% secure in this case (please correct me if I'm wrong). As with most security, the goal is to make it harder, so the 99% don't bother.
I think the best way is to prevent right clicking on your webpage, because that is the most convenient way a normal user try to download the content, and you can consider it as remark if u able to do this only as you are never gonna be able to stop a computer geek or hacker people from downloading it, because once the content is on the internet, it means it is in the public domain already...
Put the content on google drive and make it download protect. This way people can only see your documents, pictures but cannot download it.
DRM solutions are available today. It makes the video viewable but not downloadable.
What is DRM?
Digital Rights Management (DRM) solutions are software programs created to help people protect and control their valuable digital content, whether it's documents, videos, images, or audio files.
Check out this. Hope it's helpful.