Today, Yahoo disclosed its receipt of three national security letters (FBI requests for data that Yahoo is normally barred from disclosing) and published redacted copies of the letters online.

Yahoo says that this disclosure “marks the first time any company has publicly acknowledged receiving an NSL following the reforms of the USA Freedom Act.” That bill, which passed last year, was created in an attempt to rein in government bulk data collection and allow companies to challenge gag orders relating to National Security Letters.

While the letters released provide very little insight into specific U.S. government requests, today’s disclosures still shed some light on the FBI’s deliberately secretive process of gathering user data. For example, Yahoo is still required by U.S. law to disclose the total number of NSLs it’s received in brackets of 500 — a requirement designed to obscure the number of requests received.