Invisible iframe CSRF PoC (vs digg.com)

Make sure you're logged in to Digg.com, then click the "Test" link below. Now go to your digg history, and see for yourself.
Clarification: The submission I chose for this PoC was absolutely random.
This was tested on Firefox 2, 3 and IE 6 successfuly. Failed on Opera. I don't know about the rest, but the thing is that this code could be "ported" to any browser. All it would take is careful measurements and a PHP script that checks the USER_AGENT string.
View the source to see how this works, or go to my blog to read the details.