SteamRep

SteamRep is a non-profit site that partners with community administrators to improve the safety of game-related trading. The site was created by Ðiego and, through the help of trusted volunteers and community admins, it has grown into the most popular scam prevention tool for Steam trading. SteamRep gathers scammer reports from a number of high-profile trade communities, as well as hosting its own forums to allow for reporting.

SteamRep supports Dota2 trading and began taking scam reports from the Dota 2 community in June 2012, soon after the Dota 2 store was launched.