I was also thinking of the same. Trusted members of the forum could be imitated by these Guests users and can therefore be a vehicle for them to scam gullible people. Trust ratings are displayed on the left and I get that, however some people are still too lazy to do a bit of research before engaging in trades that they think is a win for them.

Also, I noticed that you can no longer create usernames with spaces on the new forum. A good idea since some trusted forum usernames could be masked by spaces and small symbols, too.