What's hilarious is that a moderator can easily, within a span of a few minutes, verify every IP address and such in this thread and see who is posting from within the same office/from the same computer connection. That's what they do on most normal forums where multiple identities aren't legal.
I've actually done this. It's even easier than you think. The admins and moderators have a little rollover tab that are invisible to other members that tell us instantly the IP address from which the poster posted. We can also easily access the entire IP posting history of any poster. We sometimes let people us multiple identities because some senior posters want to ask a question that would embarass them. Other times, we let it slide just because people come up with some hilarious stuff when they are incognito. We don't ever allow shilling, however. Actually, I kicked the agents for a fairly well known showroom outta here a couple of years ago for doing just that. The email exchange between us makes for pretty entertaining reading.