To be honest, I don't really mind it. I learnt lots of stuff about their personalities that I didn't know before, but then my other MCs started getting annoyed with it. So, to keep all of my other MCs happy, I got Alaska and Lucy twitter, so they could carry on their argument online and not annoy the others by it.
It sounds crazy, but I've got another really cool Twitter/Blogger friend (http://cupsandmuses.blogspot.co.uk/ or https://twitter.com/#!/mariellacecilia) to join in too, and her character Julian (https://twitter.com/#!/JulianTheMuse) who is so adorable, and, as Alaska called him, really, really awesome.
So yeah. That's why I have my character's have twitter accounts on the side there...