My approach to “trolling” on my communities is very simple. I don’t care. I don’t bother myself with trying to identify people as trolls – and I don’t encourage or allow my members to do it in public, either.
My belief is that good guidelines filter out the vast majority of harmful or annoying trolls. People aren’t kicked off of my communities for “trolling.” They’re banned for repeated violations of our community guidelines, such as inflammatory comments, profanity, general religious discussions, and so on.
I say this as someone who has managed communities that were targeted by groups with a plan to “troll” the community. These things happen. They come in waves. It’s a process. Identify harmful content, remove any trace of it, ban the offenders (sometimes more creatively) and don’t allow people to give them attention.