If you did not sign any sort of agreement with him (not the account agreement or power of attorney, but a management agreement with HIM) and he is registered in any capacity, and you report this to the NFA or NASD as appropriate, he will lose his registration, and probably worse. The fact that he entered trades for you in your account is prima facia evidence that he accepted the role as account manager. There are all sorts of rules about this, e.g. "know your customer" regarding your financial status, making any sort of statements about likely future performance, etc. I would urge you to immediatly revoke any agreements, contact all brokers that he has account access to and have them remove his access, and also immediately contact the NASD and NFA to determine his registration status. If he is NOT registered, then he has committed very serious securities fraud by making performance representations, accepting power of attorney (acting in that capacity, while seeking compensation as an account manager, constitutes acceptance, even without a written power-of-attorney agreement) and managing your account, and the State A.G. should be notified. If he IS registered, than you need to file a formal complaint with the appropriate body (NFA or NASD) as well.
Good luck!
Jessie