I do this from time to time. I'll come up behind them and just off a bunch of them. There will sometimes be 3 to 10 guys just not paying any attention it seems. By the time they realize what's happened I've already taken out a good portion of their team.
Haha Exactly
For example in Valparasio there is a light tower that is good sniping place. Whenever I go there to do some snipers knifing, my steps inside the tower sounds like thunder but snipers do not pay attention. I always think like WTF??? Are they too busy with killing and do not care about their own lifes?