IIRC, you can block/turn off the messaging on the entertainment console. Virgin has had the messaging thing for a while now. There are chat rooms if you happen to get seated away from your friends. I thought it was a neat feature, though it seemed like everybody on the plane was more interested in watching movies than chatting on it. I think I'd use it send an anonymous drink/food to a completely random person on the plane just to make someones day. You can't really see the people that are more than a few rows away anyways.
I'm wondering what happens if you try to buy an alcoholic drink for an underage person. Will they refund an already made drink, or do you have to drink it? Do they go and check id first? That would make things more awkward.