I am aware I may be asking a really stupid question, but what is a troll? I know the under the bridge sort but i'm guessing the HHO warnings aren't about them!!
People who come on here intentionally to sh1t stir.
They either post something like 'My pony has 3 legs, fifteen eye and a second tail coming out of its back - is this normal?' In this case, almost all of them have a friend/relative/lover who is a vet and says this is fine.
Or they just post on other peoples posts looking for trouble.