Could possibly start by not allowing demo accounts in 'Trading Systems' and a compulsory section that states broker name, account number and investor password.
Education is the best defense, people should know not to invest in a demo account claim, and insist on an investor password so they can follow the system for a few months before investing / trade copying.
As for the spam emails, best bet is to block them is spam filter... not much you can do about an email address that's already out there. (you can filter all emails coming from people not in your address book, and then when you have a chance, white list emails in the spam folder that are legit).
For every loss there should be at least an equal and opposite profit.