If you ask about protection against scams, there's none. You have to be very careful and use escrow when buying or selling.
Also look on other users' trust feedback, it can give interesting info.
Some would argue that safety protocols like trust feedback and trust flag serves as protection against scams.
The idea that the forum does not try to protect users could pass a wrong message to newer members. The forum puts some community oriented process in place to protect users especially newbies and guests from falling for scams. It is not just moderated, so there would be no action taken if you fall for scam.
Trust feedback is also not moderate and can easily contain false information too (usually retaliatory feedback, but still...), so it's far from an ultimate tool.
So while you are somewhat right (my wording could have been softer), do stand to my point. I don't want to give the wrong impression one has a safety net, when no actual actions are done to recover the stolen funds/items (there's still an action: the scammer will probably get a flag, not that it matters that much for the one if he runs away with something valuable).