I know that there aren't any US laws explicitly stating that Americans cannot participate in ICOs. The ICO issuers ban American participation in fear of future regulations. The SEC statements regarding the DAO only refer to the DAO specifically, but suggests that some, not all, ICOs may be considered a security. But are you committing fraud by circumventing the ICO issuers restrictions with a VPN? Thoughts? This isn't regarding the ICOs that now require KYC.
ICO's developers doesn't really care if you are from US or anywhere in this world as long as they'll have another investor before.
But seeing some sample on how the regulations are tough and people who are sued for not following what US is implementing about ICO's they totally scared of it now.
In what state you live? you must ask someone or join a community near you and ask them about this thing. I'm thinking two sides on it and I don't want to give you trouble if you violated any rule cos' it can certainly give you sanctions.