IMO, trolling is when a non-regular member (usually) posts a question JUST for the purpose of a reaction. (sometimes it's a member with multiple accounts who's bored).
If you look on my questions, the first is about a kid throwing ketchup at McD's. That kid was a troll. He posted a question asking what he should do to rebel against his mom, because she punished him for squirting ketchup on someone. He was not interested in answers, just wanted to stir the pot.
I feel the same about some of the abortion questions. Brand new account, first ever question - they somehow find MP and then say "hey, thinking about an abortion". Boom, pot stirred and board explodes.
I distinguish those from the "am i pregnant" type threads b/c those moms are likely truly asking, but just not thinking it through very well before they post. Imagine if I posted "What day is today", instead of simply looking at the calendar. (granted, some of the pregnancy ones involve more detailed women's repoductive system issues)
To me, a troll is someone not here for the purposes Mamapedia offers - rather they're here to get a reaction.
Just like a bully is only in it for the reaction, if you ignore a troll they go off to another board (because they're bored here).
Usually, I'm pretty suspicious if it's a new account (or only has a couple questions), they have answered none or very few, AND their first (or first few) questions all seem...dramatic.
I mean your first question was about a court case in the news. My first was about McD's kid. But what **brought** me to MP was the fact that my kid was teething and I didn't know what to do. I googled and started going through various sites - and stumbled upon this one. I liked the teething answers from all the different moms b/c I could find one that fit our family, and also see if this was a well accepted idea, or whether other moms could easily poke holes.