Unfair friends

I have recently been ambushed by teams that seem to be using the friends support factor to make them bullet proof to all but the toughest teams.
Not sure of rules or ettiquette but ten, twelve and up supporters skews the stats unfairly it seems.
Should there be a max of maybe five or so.
What have you done to the game, since changes its much harder work to play for free.
It's taking the fun away, not sure how much longer I can be bothered, too much like hard work.

Maximum possession advantage is 15% no matter how many supporters they have watching.