Do you get the sense those that may be "professionals" are very good at what they do? Subtle and low key?
Some, maybe. But I think it's more likely that they work together in 2 or 3 man teams, playing off each other.
Find two people on a thread that disagree and have one troll take one FReeper's side while the other troll sides with the other Freeper.
Then escalate the argument to the point that it deteriorates into personal insults.
Putting us against each other.