Multi's scamming and unloading FG quick is a problem (at least in USEAST HCL) I haven't been scammed by anyone in years, but I see alot of people complaining etc. My proposal:
Log IP Addresses. If one address is used by multiple accounts, put a flag on that account. If sufficient evidence is found that said accounts are in fact the same person, close said accounts.
Note: the opposite is not true, that is, if multiple addresses use 1 account that is fine (i use 3 different cpus to access JSP, one at work, one at home, one at parents house).