You should only be able to disable your own icons in my opinion. Like Amamin said, people buy/grind these to show them off to other players for brownie points. So why punish the players who grind for/buy them??
I can understand that they block and hinder your visuals. So just make it one sided.
As to the point of it being confusing/misinterpreting other players as teammates, etc... I agree it can be confusing AT FIRST. However, after two or three other occurrences it should be easily learned that all players can use these whether friendly or not. Basically just one of those "learn as you go" things in GunZ. Just like Kstyle was learned and understood.
