The US government and all the major carriers have agreed to put together a database of stolen phones to halt the theft and sale of taken devices. As reported by the WSJ, T-Mobile, AT&T, Sprint and Verizon are all on board, and when a phone enters the database as lost or stolen, no other carrier will provide voice or data service to that specific unit — rendering it near-useless.
The idea here is that it makes it much harder to use a stolen phone, and so reduces the market for these goods. The plan is still a ways from being completed — the individual carriers will roll out databases in the next six months, and they’ll be tied together in the 12 months that follow.
Once this network goes into place, it’s also doubly important that you know the provenance of a second-hand phone you buy. Be careful about buying over eBay, as it you unknowingly are faced with a stolen phone, you could have just dropped some big cash on something that won’t work.