I don't mean to bring up the whole topic of phone calls by passengers in flight, but one concern I have is that a lot of people will be wearing those NC headseats while they chat. The problem then is that they are likely to talk a lot louder than they normally would, since they can barely hear their own voice. This is a problem with cell phones generally, since they are configured not to waste power by playing the speaker's voice back into the earphone, as landline phones usually do.

This whole area of inflight WiFi is going to be hugely controversial: phone calls, porn, violent movies and games, confidential data transmissions, harrassment of other passengers...and probably some controversies no one has even thought of yet. FT might even want to have a separate forum for this.