Ask HN: Why do you (or don't you) have contact info in your profile?

I quite often look at users profile to see who they are. Some have an e-mail, some have links to their startups or blogs, and some haven't filled in anything.

I was wondering why you put your contact info in your profile and what kind of communication you would approve of? Are you only interested in work-mail or don't you mind a friendly mail about how great your hair looks? Do you actively communicate with other users, or have you done so by shooting them an e-mail?

It would be interesting to shed some light on how many friendships/partnerships/random net acquaintances are made on HN.

So what's your story?