Does it prevent click fraud? I wonder if you could place +1 inside a div with style="opacity:0" and position it on top of a link saying "Free cheese" or similar.
Edit: you can. This example [1] has opacity:0.3 so you can still see it. It seems as though it would be trivial for an attacker to put the +1 button over every link on a page. You may even be able to have one tracking the mouse cursor.
Edit: you can. This example [1] has opacity:0.3 so you can still see it. It seems as though it would be trivial for an attacker to put the +1 button over every link on a page. You may even be able to have one tracking the mouse cursor.
[1] http://jsfiddle.net/prJG8/1/