You're good aren't you, dear reader? You wouldn't speedhack in the corridors, wallhack in a test, or aimbot a dog's ball, would you? No, no, of choose not. Then you have nothing to worry about. But those scruffy herberts you dutifully report to the prefects, those lot are in trouble.
Valve have expanded Steam's banning to allow developers to easily ban ne'er-do-wells from the online sides of their games, without using Valve Anti-Cheat. Rather than being automated, the new 'Game Bans' (catchy name) rely on devs reporting players to Valve.
As Valve explain in a support article, they let developers ban "disruptive players" - not limited to cheaters - in the same ways as VAC bans, such as blocking them from their game's multiplayer. However, Valve are quite clear, "It cannot prevent the user from launching and playing the game offline. It cannot prevent the user from using Steam."
The self-reporting is a concern for some as, in theory, a player could be banned because of a personal vendetta. As Valve say:
"Game developers inform Valve when a disruptive player has been detected in their game, and Valve applies the game ban to the account. The game developer is solely responsible for the decision to apply a game ban. Valve only enforces the game ban as instructed by the game developer."
However, Valve go on to explain, only approved devs can access this new style of banning, and the power can be taken away. "If Valve determines a game developer is abusing the ability to apply game bans, Valve can remove the ability for that developer to apply bans in the future." Folks who feel hard-done-by should first try the devs, then turn to Steam support if they still feel they wuz robbed. Anyone who abuses that won't have the power for long, in short.
In practice, we should see fewer awful people around in online games, which is a change I always welcome. I was glad to recently see that the license agreement for Killing Floor 2 explains that if players cheat or are abusive, Tripwire Interactive will remove their CD key and tell their mother.
Developers could have cooked up their own ban systems before, but this way is far easier.