The latter, both online and in real life.
I avoid confrontation whenever possible, but there are some things I just can't let slide. But I try to approach them rationally, trying to keep emotion from clouding my thoughts.
I'm all kinds of unstable. Sometimes I'm a gigantic pushover people-pleaser, and other times if someone looks at me wrong I'll bite their head off. It just depends on my mood. I have a daily/weekly/monthly bullshit limit and I turn into a real wench when that limit is exceeded. I wouldn't call myself confrontational then, though, by any means. Just volatile and snarky.
Overall I try to be nice. I'm kind of shy and reserved, but I'm not necessarily unfriendly.