Not everyone of them, there's always a few Pred players that limit themselves to claws and spear (which is a bit difficult to use, if your not close to them), myself included. But then again, I play on the PC, so, yeah.... Either way, got some more fuel to the fire:
VeTeRaN_[RUS] - Pred, Plasma spammer; guy must think he's a kangaroo, 'cuz all he ever does is jump around going nuts with the P.Cannon.
vega.plius.2010 - Pred, Plasma/"e" spammer; I noticed this dude seemed desperate to get T.kills and S.kills, and he always used the infamous P.Cannon.
VASYA - Pred, REAL NUISANCE. Honestly, this ****tard must be really messed up. He used a similar tactic to VeTeRaN, P.Cannon shooting everything that moved. When we complained, at the start of the next round, dude changed to our side (Marines), and then, guess what? He started team killing every single marine, completely messing up our score! Then, some other guy got fed up with his antics, and banned him from the server (yay!), though I don't know how he did it.