Just report these users. I find that the majority of trolling is done by the new users and those without an avatar.
And shockingly, those with a low post count seem to do their fair share of trolling as well, although in a more discrete manner.
Mods definitely need to be more aggressive towards these people. If a thread is getting derailed, step in and give an unofficial warning if necessary before it gets out of hand. Also you should give warnings/bans for those there just to annoying people.(Mods know who I'm talking about)
If many people are complaining about a certain users posts even if they dont' report them....please take action.