If you're feeling brave, Twitter is (once again) letting you receive direct messages (DMs) from any old person. As before, you'll have to opt-in by ticking a box in the settings -- but once you do, even folks who don't follow you can send you a note. On top of that, you can now reply to anyone who DMs you, even if they're not a follower. That's a big change from the status quo -- previously, you've only been able to receive messages from people you follow, and send them to those who follow you. To drive home the point, Twitter put a Direct Message button front and center on your contact page for its iPhone and Android apps.