We do copy various data by Ctrl+C for pasting elsewhere. This copied data is stored in clipboard and is accessible from the net by a combination of Java Scripts and ASP.
Just try this:

Copy any text by Ctrl + C
Click on this link: http://www.friendlycanadian.com/applications/clipboard.htm
You will see the text you copied on the Screen which was accessed by this web page (hightlighted in yellow colours).
Do not keep sensitive data (like passwords, credit card numbers, PIN etc.) in the clipboard while surfing the web. It is extremely easy to extract the text stored in the clipboard to steal your sensitive information.
This is how you can disable it: We can configure IE to restrict this behavior. The following settings are required-

Internet Explorer 5 and 6

In Control Panel, click Internet Options.
Click the Security tab.
Under Select a Web content zone to specify its security settings, click the zone 'Internet' where you want to prevent Web sites from accessing your clipboard.
Click Custom Level.
In the Scripting section, under Allow paste operations via script, click Prompt or Disable.
Click OK.


Works with Internet Explorer and Netscape.
I dono abt the other browsers..........
Moreover only text could be retreived fr the clipboard.(not pics)