Still relying on AT&T's aging 2G network? Better hurry and make those final calls / texts. As the world collectively moves on to 4G, and even 3G in some places, 2G technology is becoming more expensive to maintain and less frequently used. Based on a new filing from AT&T, the world is being told that the carrier's second-gen wireless networks will be shut down by 2017. Only around 12% (~8.4 million people) of its customer base is still using 2G handsets, but that's still quite a few to push over to 3G / 4G. The company is promising to work "proactively" to transition them, but it stopped short of saying exactly what it would be doing. Between fear-filled notices and upgrade promotions (and the iPhone 7 or 8 by that point), we're pretty sure most folks won't hesitate to step into the next frontier. And besides, how much longer are those 2G handsets going to actually turn on?