Valve’s stepped up its punishment for players who are caught cheating on VAC-protected servers, or are banned by developers through Steam’s ban system.
In an announcement on its support page, Valve states that if a player has been banned by the VAC (Valve Anti-Cheat) system or have been banned from a game by a developer, they be unable to purchase copies of games to be saved to their inventory through trading.
The changes are somewhat minor, as they don’t expand the number of players banned, but developers on Steam should be aware of them as players unable to trade specific games will likely appeal to that developer for support.
In addition, if a player directly gifts a game to a player who receives a game ban, that player is prevented from gifting copies of that game in the future. Valve states that this is meant to directly counter the practice of banned cheaters hoarding copies of games on their main account, then passing them to alternate accounts so they could bypass the ban and continue cheating.
The only concern Valve hasn’t addressed is what happens to players who gift games to friends who are subsequently banned from that game for poor behavior or cheating. Those players may not be participating in cheating schemes, but would still be unable to trade copies of that game again.