Restitution measure removed to protect market sanctity.
In the past, when bilked out of valuable items by a nefarious scammer through Steam trading, users could make an appeal to have their lost property restored. This is no longer an option, based on an update to the service's "Scams FAQ" page.
According to an entry in the FAQ, Valve has decided not to restore lost items (which, being wholly digital, could simply be generated again) because of the impact on the market value of items within the community. "Our community assigns an item a value that is at least partially determined by that item's scarcity," the entry reads. "If more copies of the item are added to the economy through inventory rollbacks, the value of every other instance of that item would be reduced."
The entry goes on to indicate that Valve feels it has met its responsibility to provide enough information for users to be able to protect themselves: "We sympathize with people who fall victim to scams, but we provide enough information on our website and within our trading system to help users make good trading decisions. All trade scams can be avoided."
Indeed, Valve does provide a wealth of information regarding scams perpetrated using their platform. The Scams FAQ describes fifteen different scams, red flags users should look out for, and a variety of other tips for responsible trading.