I think going as far as taking information about people breaks their anonymity.
I believe the users should be allowed to pick-and-choose what information they share, aside from the information already public (
http://www.whatsmyip.org/more/ ).
If you look at twitter, they have this option to allow yourself to be verified (
http://twitter.com/help/verified ).
Using an option like what twitter offers, will give a trader more credibility but not more trust.
Trust would still have to be earned through trading.
Information, if chosen to be verified, will be stored on a database (with a website) over a hidden private network (VPN, NO
NOT TOR) between the site owners. In order to access the information, you'd have to get in-contact with the site-owners.
There will also be a private chat (forum, IRC...something...I don't know yet) that will let users discuss trade privately.
Ideas are still going off in my head, and the more feedback about this project the better.
Oh yeah...I'm not an artistic site designer in any way....
Development on basics (and maybe some of the advanced parts) of the site will be done over the holidays where as I will only have an iPhone with 3G for 5 days.