Trolls are annoying yes, but it's when they team up that it really starts to suck.
Had a situation where 2 buzzards and 1 cargobob (with car attached, for the purpose of dropping on top of me).
I was at the Kortz centre so I had plenty of cover, shot at the cargobob's cockpit and he immediately flew away, then turned my attention to the rocket spammers, 2 shots from my sniper and both pilots were KIA.
I had cops all over me by this point, so I started to jump down to ground level and find an escape route out the back of the Kortz (all the trolls had respawned round the front, and were heading my way), only to see a police chopper landing to drop off some SWAT guys, so I quickly shot the pilot and all it's gunners, stole that heli and escaped my ass out of there.
Sent all the would-be trollers a smiley face.
Moral of the story, try to avoid getting dragged into a tit for tat fight, put them down fast and hard, get gone. They usually leave you alone once they realise you can actually fire back at them, they seem to keep coming at you until you do some damage to them, then they do one of two things, leave you alone and move onto their next target, or leave the session altogether.
If you stand around and let them kill you, it's on you, fight back, even if you die, you tried to better your situation.