We consider ourselves fairly cautions Internet warriors. We know when to watch out for malicious links and tread lightly during those times. But this hack will still bite even the most cautions of link followers. It’s a hack that changes where a link is sending you after you click on it.
So who’s vulnerable to this kind of thing? It sounds like everyone that’s not using the Opera browser, which has been patched against the exploit. There are also some updates at the bottom of the post which mention that Firefox has been notified about it and Chrome is working on a patch.