I visited the board right before it was taken down yesterday, and my Firefox went nuts, getting cookie requests from places I'd never heard of and so forth.

The attacker has inserted IFRAMEs at the top that caused a cascade of other things to load, yet strangely, nothing ever appeared on my screen. The evil images and such were still part of the page, and thus showed up in the list of AdBlock-able elements. I have no idea why it happened this way, but I added another 50+ rules to AdBlock to cover it. The next time I stumble on a hacked web page that's playing the same game, I'll hopefully not even notice it!