Undertaking legal action ... against the US authorities? Good luck. An ETH ICO could actually potentially provide a lot of funding (given how people will still throw ridiculous amounts of money into any ICO at this point). But taking on the feds?

This, unfortunately, isn't like offering online gambling from Antigua. Money laundering is apparently taken much more seriously, and given that BTC-E had no mandatory KYC, they probably shouldn't have openly accepted US residents. Pigs, man.