In a loosening of rules surrounding national security letters, the FBI generally will let companies reveal warrantless requests they receive for customer data the agency seeks as part of national security cases, President Barack Obama's administration announced Tuesday.

Under the national security letter program, the FBI can bypass a judge to get subscriber information, telephone records and other customer details from businesses. Until now, companies typically couldn't publicly disclose information about the national security letters they received—even the fact that they'd received one.

Businesses, however, must wait at least three years to divulge the requests under the updated national security letter policies. The agency will “presumptively terminate national security letter nondisclosure orders at the earlier of three years after the opening of a fully predicated investigation or the investigation's close,” unless an FBI manager decides disclosure is inappropriate, according to a report the Obama administration released on surveillance reform.