Massively wondered why public dungeon boss bots are so hard to stamp out in ESO. I thought I would answer this in a blog post, because any comment I posted would be lost in the noise.
I don’t have any first-hand “inside baseball” knowledge but from what I’ve pieced together from years and years of developer posts about how bots are dealt with, this is my guess on why they can’t just snap their fingers and make all the bots in public dungeons disappear:
Some percentage of the bots are stolen accounts, which means if they ban the account or the credit card, they are not doing anything to the malicious user, they are only affecting a legitimate customer.
Some percentage of the bots camping public dungeon bosses are probably real people. Not all of them are bots. Perhaps none of them are bots. If you just stand there next to the spawn point with everyone else and spam an ability key (say, the lightning spell if you’re a Sorcerer), you will look exacty like a bot, because the very second the boss appears, you’ll start attacking. In fact, that is about the only way you’re going to get credit for killing that boss and get some loot and/or an achievement. If you do that manually it is a perfectly legitimate, efficient (if cheesy and boring) way to grind out loot to turn into gold and become rich.
The point is that the developers need to spend time to sort out which players are actual bots and which players are just super efficient and/or super lazy. Only then can they start banning IPs or credit cards. Also, it could be gold farmers playing manually, too. Some kid in Korea might be sitting there getting paid 2 cents a day to stand in one spot and spam an attack key over and over and over again. How are they supposed to tell the difference between that kid and someone who is just collecting some extra loot while watching television?
(Personally I think they need to lay down a giant AoE that kills anyone who stands still. That is a tactic that Rift used for people who exploited Onslaughts. Or, you know, get rid of public dungeons. That would be the smart thing to do.)