Why not create a different status for the users who want to be "verified" sellers so we could at least do something to prevent bad experiences. These users could pay say 5$ to obtain that status and Steve would mail them a little card with a password. Once the user gets the password he would email it back to Steve, which would mean the address actually exists. Then steve could turn their name purple or any other color, indicating this is person's address is verified. But that's not all. People who buy from this user could PM Steve their bad experiences with them, so he can turn their names black or at least back to orange meaning they no longer can be trusted. The only downside to this is the extra work for Steve, but maybe he could delegate this task to someone of his confidence. The idea is to get buyers to prefer a verified user instead of the rest of the users, which in turn would make more sellers get the "trusted" status. Well, lets' hear everyone's opinions.