Yes, I am talking about arbitration, but from reading that page, it sounds like the company tries to serve as arbiter instead of giving people the tools to pick an independent outside arbiter who is trusted by both parties. It's hard to prove to the company that I sent a bitcoins to someone else, but if with a trusted service like the Bitcoin Market, he verifies that I have sent bitcoins, but ideally there should be a way to prove to him that the other person really sent the payment for the bitcoins. With Pecunix I can temporarily make a transaction public and send the arbiter a link to it and with Liberty Reserve, I can send the payment details to the arbiter to prove that payment was made. Anyway, that may not be clear, but I don't know how to explain it any better.
This is a russian system and for the russian authorities, at least, it gives the necessary russian documents for proof of payment. (But these documents have disputed value since Russian law has no concept of electronic money in general.)
About WM-currencies of other countries can't say anything, sorry
In any case, usually a deal based on trust owner webmoney purse and this refers to his "certificate of the seller" where are the rating of the seller.