At PSP Chicago they moved the spectator line back about 5 more feet, so it was a good 10 feet away from the netting, and no rostered member of the teams playing are allowed on the spectator side coaching. I think the overall effect is what Nick is referring to - the sidelines just become a loud distraction for most players with a low signal to noise ratio (meaning: most of what you hear is unreliable/BS)
of course, this has positives and negatives. In the positive side, it allows spectator to cheer and feel like they're interacting with the game, while reducing the impact (note: I said reducing - you're not going to eliminate the impact completely)
On the negative side, you end up with a barely controlled mob being rude and beligerent to players, refs and other fans. With all that going on and considering paintballers aren't exactly known for their calm, placid temperments, how long 'til the shouting turns to violence? I know it's happened at divisional xball games already.
I wonder... Would paintball hooligans rioting before the big CPL showdown be a step up (towards footie/soccer) or a step back?