How does this website know I have copied data (and how can I stop it?) [closed]
Navigate to the following website: - and look at any product. Here's a TV for example:
Now select the title of the product ("PANASONIC VIERA TX-49DX650B Smart 4k Ultra HD 49" LED TV") and you'll see a little box popping up, telling you that they have a price comparison service, clearly in an attempt to stop you from googling the product and finding it cheaper elsewhere.
This is a very clever piece of code, and I don't really begrudge how this retailer is using it, but it upsets me that a website knows when I am copying information from it. How are they doing this, and how can I stop it? I know it isn't a Flash applet because I have click-to-run enabled.
62 Answers
They are using Ajax Javascript on their webpage extensively. Ajax is capable of monitoring the clipboard.
A script can easily be made to check if the title has been copied to the clipboard and display a popup, as they did here.
To stop it, disable javascript execution of websites. Depending on your browser you may be able to stop it just on this website, but please understand that websites like this who have javascript so well buildin, will stop to function correctly. You are likely not going to be able to order on that website anymore for example.
1Looking at the code on the page, they are using Javascript to detecty a copy method.
If you look at this link, there is a good tutorial on how to implement this function yourself.
From the article (in case the link ever becomes dead), something like this will work:
<html>
<head>
<script type="text/javascript" src="jquery-1.4.2.min.js"></script>
<style type="text/css"> span{ color:blue; }
</style>
</head>
<body> <h1>jQuery copy, paste and cut example</h1> <form action="#"> <label>TextBox : </label> <input type="text" size="50" value="Copy, paste or cut message here" /> </form> <span></span>
<script type="text/javascript">
$(document).ready(function() { $("#textA").bind({ copy : function(){ $('span').text('copy behaviour detected!'); }, paste : function(){ $('span').text('paste behaviour detected!'); }, cut : function(){ $('span').text('cut behaviour detected!'); } });
});
</script>
</body>
</html>It is worth noting that by changing the referenced object $("#textA") that the actions are bound to, you can change which elements you detect the copy of (for example, bind to a DIV, a span, a whole page etc).
You can also change the action by modifying the $('span').text('copy behaviour detected!'); code inside the action function. Instead, you could use alert('copy detected');, you could call a function, show (or hide) a DIV containing info, open a popup, clear the users clipboard so the copied text doesnt actually copy, pretty much anything you like.
To stop this happening, disable Javascript. However, if you do that, nothing else will work. Looking at the code on Currys website, it's not posting back to their servers that you copied - so while the webpage alert you to the fact that you're coping text, the website owners dont appear to be logging or recording this anywhere
2
