the scanned license/ID thing is something that another forum I used to go to uses. It used to be invite-only, but now I think accounts just need to be 'verified' before they can post buy/sell threads. It has worked reasonably well for them, I don't think there have been any major thefts, and 4 and 5-figure items are frequently being sold there. However, it must be noted that it is a marketplace forum, and may not work as well for GBs that may have hangs and hiccups.