I know they are hard to trust after the experiences we've had with sheep and other marketplaces. TCF stands for Tor Carding Forums, it is a well stablished underground community with more then 14k users that has been online for almost two years, his owner just started out with this new marketplace which looks good so far. As most of the flow right now is from TCF, the marketplace has so far a lot of fraud related services, there's already sellers from other marketplaces migrating into it, so you can also find drugs, chemicals, weapons, etc.. what you would normally find in this kind of markets. The escrow service is fast and reliable.