I don't think it's illegal to play. It's just illegal for a US financial institution to transfer funds to an entity that runs an online poker service. Or something to that effect.

It's not illegal to play poker online. I'm not an expert in the legality/legislation of online poker but the PPA[1] is a good place to start.

[1] http://theppa.org/

Playing is not illegal, but transferring money overseas can amount to wire fraud and money laundering. When Silver was doing his best poker work, the laws were far muddier.

Yeah, but you can play on foreign sites. Just use BTC and you should be safe.