Calling cell phone theft a "growing epidemic," the Federal Communications Commission announced today that all four major US cellphone carriers have agreed to deny cell and data service to stolen phones, and contribute the serial numbers of those phones to a national database. The Wall Street Journal, Bloomberg, USA Today and The New York Times each appear to have been briefed on the plans from both official and unofficial sources ahead of a formal announcement in Washington tomorrow, and here's what they've heard:

• Each individual cellular carrier will build its own database over the next six months, and then the four separate databases will be joined within the following year and a half
• Senator Chuck Schumer proposed a bill that should make it illegal to circumvent the database (via USA Today)
• Companies have agreed to begin blocking devices within six months, according to FCC Chairman Julius Genachowski (via Bloomberg)
• Since SIM cards can be changed out, carriers may need to check a device's unique identifier against the database to determine if a phone is stolen (via WSJ)
• Regional carriers may join the program within that two-year timespan (via WSJ)
• Carriers have also agreed to educate their customers about securing their personal data

Without cellular or data service, phones would certainly become a less valuable target for thieves, but there are plenty of questions still to be answered, and we're curious about possible potential for abuse: tracking unique identifiers has often been a privacy issue, for instance. We'll be keeping an eye out for the official announcement tomorrow.