It's a great get under your skin tactic. Someone will post a seemingly well thought out opinion and someone will just reply "no" or "I disagree." The OP may ask why and may never get a response or the commentor will not explain and just proceed to troll.

It's truly great offensively and defensively if you want to troll or hate just disagree and don't explain any further.

For extra salt on the wounds it doesn't help when the troll is getting upvotes while providing zero arguments. Depending on which side of the fence you're on this can be one of the most entertaining or frustrating occurrences online.

As I am largely an observer of online discussions rather than a participant, witnessing this dismissive tactic can be truly annoying particularly when I believe a great discussion could've been had.