The sad thing is that a lot of them probably believe they are the good guys, and that they'll be able to clearly tell when they start crossing a line towards The Dark Side. We all live in our own bubbles, after all.
If you've never seen The Boxtrolls, it's a moderately funny newish kids movie, but some of the parts that I enjoyed the most about that movie were the scenes with the two evil henchmen. I enjoyed it because they'd convinced themselves that they were the good guys, fighting the good fight and all that. But as the movie goes on their perspective slowly changes as they become more aware of the impact they're having on the protagonists.
I firmly believe there are very few healthy people out there who honestly want to watch the world burn, we should all be aware of the impact we're having on those around us. It's easy to write off an opposing side as evil do-er, but in all likelihood they see themselves as fighting the good fight just as much as you do.
Don't worry. It's ok because the Good Guys(tm) would never do anything bad. They would make them Bad Guys(tm)!