Although not a tech site, everyone here has probably heard of the NY Times third party ad supplier getting hit, and injecting an attack to visitors from a poisoned advertisement. *
I use Adblock mostly in self defense, along with NoScript, because I don't know who is pushing the ads, or what their policies are. If AdBlock is going to vet advertisers and guarantee safe content, then maybe I will loosen up a bit. But I'm still leery, as even certificate authorities these days are getting gamed.
In general blocking anything except the web content I'm trying to view, seems best practice.