Since bankers know who other bankers are, a system like the mod_virgule that powers Advogato [1,2] would solve this problem, though the site would need some tweaks [3] .
The attraction of the system is that, if you keep an eye out for clever attacks against the model (i.e., something like security fixes), and if certification activity by "good" users is essentially sane, then such a site needs no ongoing moderation by the site owners.
[3]: The codebase hasn't been touched, and there's a form of attack that, while it is known how to solve it, has not been fixed on the main site; also the UI has some cruft and doesn't support an HN-like leaderboard view - the codebase is fairly simple, though, and lots of people have hacked on it over the years.
The attraction of the system is that, if you keep an eye out for clever attacks against the model (i.e., something like security fixes), and if certification activity by "good" users is essentially sane, then such a site needs no ongoing moderation by the site owners.
[1]: http://svn.dprg.org/viewvc/mod_virgule/trunk/
[2]: http://www.advogato.org/
[3]: The codebase hasn't been touched, and there's a form of attack that, while it is known how to solve it, has not been fixed on the main site; also the UI has some cruft and doesn't support an HN-like leaderboard view - the codebase is fairly simple, though, and lots of people have hacked on it over the years.