In March 2015, the Enforcement Bureau (Bureau) of the Federal Communications Commission opened an investigation into, among other things, T-Mobile’s practice of de-prioritizing its T-Mobile and MetroPCS UDP customers during times of network "contention."
The Bureau’s investigation confirmed that during "contention," T-Mobile employs a "Top 3 Percent Policy," that de-prioritizes the data usage of customers on T-Mobile and MetroPCS UDPs who have exceeded a certain threshold of data usage.
T-Mobile referred to such UDP customers as "heavy data users." When the Top 3 Percent Policy is applied, a network algorithm controls the heavy data users’ network access including, most notably, the speed of their data throughput.
Further, the FTC said that T-Mobile’s public disclosures about the de-prioritization policy prior to June 2015 "were not sufficient to fully inform consumers about limitations imposed on the UDPs, because they did not identify the data usage threshold that would trigger application of the policy, did not explain how the policy could impact a de-prioritized customer’s ability to use their service, or discuss the data throughput speed reduction a de-prioritized customer could experience. "