Facebook is where I hang out in my underwear, metaphorically speaking. That's why I'm unfriending all my business contacts.Here's the mental picture I've created for the Big 3 social networking platforms I use.

LinkedIn is a suit and tie. It's a conference room for business meetings, and people tend to be on their best behavior.

Twitter is a sports coat and jeans. It's the hotel bar at a security conference or trade show. Technically I'm still at work, but there's alcohol. The industry chatter, shop talk, and self-promotion gets salted with gossip, mild flirting, and swear words. You might even see a fight.

Facebook is boxer shorts and a T-shirt with burrito stains. It's the couch where you sprawl out to watch "Family Guy," eat Phish Food straight from the carton, and leave your socks laying around.

Facebook was the first social networking platform I joined, and when co-workers and business associates found me and sent friend requests, I was delighted to accept. Then I started using Facebook to communicate with friends and family in earnest, and I realized how many details of my private life were accessible to people I wouldn't normally share them with.

So please don't be offended if we're no longer Facebook friends. We can catch up in the conference room or at the bar after the keynote.