As previously reported, the Federal Communications Commission last month released responses from the 15 major wireless carriers concerning their data retention and privacy practices, particularly with respect to location information.

In doing so, the FCC Chairwoman announced that she had asked the agency’s “Enforcement Bureau to launch a new investigation into mobile carriers’ compliance with FCC rules that require carriers to fully disclose to customers how they are using and sharing geolocation data.”

According to Communications Daily on September 8, industry officials said that the Commission sent “letters of inquiry” (“LOI”) to wireless service providers, including both carriers and mobile virtual network operators, seeking additional information about their data privacy and data retention policies. Such letters are generally the first step in an Enforcement Bureau investigation; unlike the earlier letters, the FCC does not publicly release LOIs initiating such investigations.