I've got both. Twitter is my biggest addiction, though. And you can control who sees your posts with the private option. Mine isn't on private, but that's because I don't post anything I want to keep private.
I follow a bunch of people. Real-life friends, Dis friends, various other online friends, celebrities. The writers for some of my favourite shows have accounts as do some of my favourite actors. As an aspiring writer, getting a reply from some of the TV writing idols is a huge thrill! I actually had a legitimate back-and-forth conversation with Jim Campolongo (a writer for White Collar) a few weeks back. Even a few of my favourite actors reply on occasion. Though, they're not big super stars, just TV stars. It's super fun.
I'm pattimalone on there if anybody wants to add me. Just tweet me so I know who you are!