[alightsoul]

Wikipedia maintains a quite exhaustive list of them to prevent spam and they also block vpn IPs as soon as they're found.

[fc417fc802]

That is an entirely different matter. They only block (AFAIK) editing which is a scenario where PoW would not be expected to solve the problem. What I was talking about here is IP banning as a (boneheaded) mitigation against high volume scrapers.