Some of us attended this years FOSDEM in Brussels (thanks to Dimitry it was *really*, *really* great).
We (at least the ones attending) got to know each other a bit better (I even got to know some pre Gentoo devs .. yeah, you), and some time after FOSDEM (I think it was ~3 days afterwards), Petteri (betelgeuse) asked me why people all of the sudden start to call him with his first name on IRC.
I think the cause for that is just seeing each other for some time (like 2 days in a row), talking to the other(s) in person makes you feel closer to him/her (you hopefully know what I mean 😯 ). Or maybe that’s just me.
After FOSDEM the virtual bonds changed, I started to call quite some people by their first name as did others.