Based on the responses thus far, I have come to the following conclusions:
I think you @prplchknzare right in that some people do intentionally poke, deliberately set out to hurt others, and in that case, they, too, are trolls, BUT I also think that @Coriolis has made a very valid point. Sometimes it's hard to tell when a poke is accidental or intentional. I think there are some people who know how to poke just enough to illicit a response, but not enough to get called out. I also think that regular people can troll the troll by not engaging and taking the wind out of the troll's sails so to speak.
I think that people who get their feelings hurt are not necessarily trolls. People with strong opinions are not necessarily trolls but people who deliberately lure others to cross their bridge or take the bait...who lay in wait with intent to harm...they're trolls.