Notably, all of Valve's competitive games—Dota 2, CS:GO, and Team Fortress 2—already require this. I'm not sure I support it, but even minor barriers help fight cheaters and smurfs.
Edit: Apparently they're not actually as strict as I remember, but all three definitely have some sort of a system.
Edit: Apparently they're not actually as strict as I remember, but all three definitely have some sort of a system.