The government's definition of illegality (rather "suspiciousness") is getting more and more nebulous.

Legal according to whom? Poker websites are a good example: legal in most of the world, but not in the US.

It's not that simple, though: legal sites have had their domains seized as well. These days any site with user-generated content is at risk although thus far they've focused primarily on hip-hop and other music sites.

This is the perfect wrong answer to a thought experiment.