A player can be highlighted on the map. Why not two or three?
In addition to helping with sabotage, it helps a lot in confirming who confuses friendship, chivalry and sappers. Sappers can also be confused with pushers.

I look for good squares but sometimes I also find accounts that are great at finding good squares but then, for some reason I don't know, don't get them. One case is one case, two is coincidence, three is likely conspiracy!
Being able to highlight multiple players removes or confirms many suspicions.