Anyone else think it'd be fairly interesting to have a revolver for the spy that has reduced damage (like 40%?) less rounds (maybe a single shot before reload? A dart pistol maybe?) and what it does it when it hits an enemy player it tracks them (for example like how you can see the intel through walls, it does that but with a player for lets say 10 seconds instead, think left 4 dead when a boomer throws up on someone and you're an infected), all enemy players would be able to see this player but the player would not have an indication they are being tracked.
This would be an interesting playstyle, track player, cloak and wait for the perfect moment to strike (since you know EXACTLY where they are and where they're paying attention to), or have a teammate do it.