It seems that in order to participate you must check a box that says you are not a US citizen. I don't know the legal implications of this, nor the reasons, but it must involve avoiding US regulations of some kind. Of course, you COULD use monero to amonymize your purchase of ETH and use a VPN plus Tor to spoof your IP and it would be practically impossible to link it to you, as far as I understand. I have no idea what kind of legal implications that would have for you.