I dusted off my old copy of Diablo 2 last summer and played for a little while. The entire multi-player experience was dominated by bots spamming ads or bots that instantly pick up any rare items that dropped.

The botting was completely out of control.

I chatted with another player who used bots to farm for rare items and he claimed to have 24+ instances of the game running 24/7 split across several machines. He would check once a day to see if any of his bots managed to get a really, really rare item.

Kinda crazy... =]