I don't really go in much for revealing my real name online, and while there are in fact pages where you can find me posting using my real name and a search for my identity will turn up details like family members, my address, etc, the odds of anyone knowing that data represents me without already knowing it represents me are staggering.
See, typing my name into Google turns up a ton of hits: only one of those is me. Pages that might contain lots of info about me will also be full of extraneous information about other people that share my name - you'll find blogs, articles, facebook pages, photobucket accounts and pictures, etc, and they're all the wrong person; if all you're armed with is a name, you're probably not going to pick the right one.
Search for this username and you'll turn up several pages of results that are in fact me, but my actual real life identity can't really be used to track me down unless you already know enough about me to do that regardless - there's just too much extraneous data to narrow down which is correct if all you know is my real name.
I would really rather keep it that way, so I'm glad I don't have an account on Blizzard's forums or any reason to create one.