Let us report people for teaming.

I'm assuming you're talking about 2 completely separate teams working together to win?  I've considered that this might be happening, but it will be very hard to call out those teams doing it.  The only thing I could think of, in order to catch this type of activity, is to keep track of the teams joining, or trying to join, the same servers repeatedly.

This will be an extremely long shot to catch.  Now, what type of punishment should these type of players/groups receive?  Ohhh boy, I'm not even sure where to begin on that one either.

Hard to see that teams are teaming and it's not just one team waiting for one team to attack the other and then take down what's left. A normal strategy in BR. 

Really???? there are how many teams out there again?? You just got surrounded ,, another  one crying over getting beat, This world I tell you. everyone carrying purses..

In order to be considered teaming, you would basically need to have two squads running right by each other without fighting.  Generally what happens is third partying, which is common in all BR games.  A team will come across two others fighting, and try pick them off while they're weak.