I talk a lot of shit online, but rarely is it mean-spirited. I'm much more aggressive online, but my personality isn't THAT different. And I have a funny story about being found online, but we'll wait just a moment on that.
I'll mention things that I've done in real life that are good, but never as a "I'm not really an asshole" measure. My best "I'm not really an asshole" measure is to say, "I'm sorry, I'm not really an asshole" when someone points out that I've greatly offended them.
So. My real life name is Mike Weaver, which is one of the most generic names you'll ever find. I was on a site once that, once I got moderator-ship, required me to change from my screenname to "Mike Weaver", and I resisted that at first until I realized something that made me understand it's not a big deal. Even then, many years ago, the internet had no anonymity. I had made the mistake of using my Real Work E-Mail to sign up for that site and didn't hide my e-mail (it was a small site at the time, like 20 members). I also used the number of my extension at work as the random number after my original screenname, since I was trying to use something pretty generic. An underage girl from that site started sending me naked pictures, unsolicited, at my work e-mail and also figured out how to call me when someone told her what the numbers after my name were. I managed to get it taken care of as "unsolicited" by the IT department and got her phone and e-mail blocked, but it caused a significant loss of face.
That's from my e-mail address and screenname.
Now, another friend of mine spent four months accidentally calling the wrong Mike Weavers in the phone book before finally getting my number. So. Finding me in real life with knowledge of my name and where I lived was harder than finding me on the internet.