That's the problem in a nutshell. About 95% of the people out there think the definition of "troll" is "someone who disagrees with me", and I don't see how you ever really get away from a subjective determination.
So...it's defined, but it's impossible to know whether it's happening unless the person specifically tells you they're trolling? That sorta seems like a flawed definition.
"Anyone who doesn't agree with my ultra progressive views that people should be able to define their own gender identity is a hateful bigot and needs to be silenced"
True, but some argue that those who support Trump, or who are against gender identity equality, are trolls.