OK, so suppose you're on Twitter and you engage with a person who has an opposite opinion. Now let's say that this other person has thousands and thousands of followers -- not a few hundred, but TENS of THOUSANDS.
The person either replies to a tweet you sent out ... or they retweet something you sent them. Realize that when they do this, you now have a spotlight on your account. And all of their followers, most of whom may be trolls who have nothing to do but harass people, are suddenly paying attention to YOU.
This is where the "snowball effect" comes into play.
Once your tweet has been acknowledged by the person with thousands of followers, you're a sitting duck. You will start getting replies from all of THEIR followers, and in some cases, harassment. And if you have a web site or blog address listed in your Twitter bio, you may notice harassing comments on that site from those same Twitter trolls.
This happened to me this morning.
One thing I will say is that I never engage with a person like this UNLESS I am fully prepared for the consequences that I just outlined above. If you are having a bad day or feel like you can't take controversy, the best thing to do is to stay away from people like this on Twitter. However, if you feel that it's important to make a point and you're prepared for the onslaught, then engage -- but do so knowing that you will probably see "the snowball effect."
My best advice is not to interact with people that are obviously on there to troll. In the case this morning, I noticed that the person in question had held up a blogger for ridicule, and I chose to respond to defend the blogger. That said, I don't do this a lot.
Hope this little tip helps, and I'd like to know if any of the rest of you have ideas or suggestions for dealing with Twitter trolls that have been effective for you.