I kinda figured this was coming sooner or later. McMansion Hell is using unquestionably copyrighted photos, but claims that they fall under Fair Use. I think that's true (but IANAL), but fair use is an affirmative defense that has to hold up in court.
It's a good concept for a site. On it's surface it looks down right like community service. It's a bit snarky here and there but, man, some of those houses invite that kind of criticism. I don't see him selling anything, just a plug at the bottom about an article he wrote elsewhere.
Maybe he should switch from using Zillow's copyrighted pictures and ask readers to send in pics from their neighborhoods. Perhaps ask people to please assign copyright to him if they do. If people know he's not making money off it and just sharing info/thoughts on ugly housing I bet people would contribute.