Okay, maybe this isn't such a hot idea from a security standpoint. But don't you think a little social profile vetting is in order before they seat people on an aircraft?
Show me a passenger whose Twitter profile is larded up with multi-level marketing come-ons, and I'll show you someone who's going to pester their seat mate about exciting affiliate opportunities in the exotic berry juice industry. Check someone's Facebook profile for a deluge of Farmville notifications and invitations, and you'll have a pretty good idea if they're likely to natter non-stop from LAX to LGA.
And I challenge you to find a better technique than looking through someone's commenting record on Disqus or IntenseDebate for telling whether they're likely to hog both armrests and kick the seat of the person in front of them.
At the very least, let's get a few smart people together to develop an algorithm that can quickly sift through the information in your profile and match you with seatmates you're going to find - if not riveting - then at least tolerable company. (Unless the airlines are already doing that, only to match you with people you'll find so annoying that you'll order more drinks. It would explain a lot.)
By the way, I'll be in the air next week heading to BlogWorld in Las Vegas, sketchpad in hand. See you there?