I think this is factually incorrect, that trolling was used for the tactic of milking patents for financial extortion, separately from the identification of the class of actors known as "non-practicing entities" who, as a class, are known for frequently employing (and being particularly difficult to constrain when they employ) the tactic. But, while the two concepts are related, they aren't identical -- trolling is an action (and trolls are those who engage in that action), while NPEs are a class of entities distinguished independently of their engagement in trolling (despite frequently also engaging in trolling.)

You don't have to be an NPE to be a troll, or vice versa.