I think what happened is a lot of people in our cohort figured out how to use the trolling techniques honed on forums and in flamewars on the general public. You can see it reflected across the web now in ways that have caused real, lasting damage.
And while I agree that we're the first digital natives, I think what screwed the pooch was a massive influx of boomers into social networks, and everything that comes from having a bunch of non-digital natives suddenly being given tools they weren't ready to handle.
Who knew a textarea and a notification system could become so troublesome?