Lashdots writes: A lawyers' group has called for greater oversight of a government program that gives state and federal law enforcement officials access to metadata from private communications for criminal investigations and national security purposes. But it's not digital: this warrantless surveillance is conducted on regular mail. "The mail cover has been in use, in some form, since the 1800s," Chief Postal Inspector Guy J. Cottrell told Congress in November. The program targets a range of criminal activity including fraud, pornography, and terrorism, but, he said, "today, the most common use of this tool is related to investigations to rid the mail of illegal drugs and illegal drug proceeds." Recent revelations that the U.S. Postal Service photographs the front and back of all mail sent through the U.S., ostensibly for sorting purposes, has, Fast Company reports, brought new scrutiny—and new legal responses—to this obscure program.