Companies that offer such programs allow customers to stream music and video without it counting toward a data plan limit, in a process called "zero-rating." In one case, the FCC was investigating T-Mobile's Binge On free data program to determine whether it unfairly favorited certain services.

Under recently departed chairman Tom Wheeler, the FCC opened inquiries into how companies might be using free data programs to anti-competitively favor certain streaming music and video services. But a new, President-Trump-appointed chairman recently took over at the FCC, and according to letters just posted by the agency, the inquiries have been dropped.

A demonstrator holds a sign in support of net neutrality outside the Federal Communications Commission headquarters in Washington, May 14, 2014.

Similar concerns were also raised about AT&T's Sponsored Data and Data Perks programs, as well as Comcast's Stream TV service and Verizon's FreeBee Data 360 program. Net neutrality advocates have long contended that such programs harm competition by unfairly marginalizing some services, and the nightmare scenario has been a competitive landscape where giant service providers pick winners and losers on a carved-up internet.

Four brief, identical letters sent to T-Mobile, AT&T, Verizon, and Comcast today, however, say the long-running inquiries have been dropped. "Through this letter, I am notifying your company that the Bureau has closed this inquiry," they read. "Any conclusions, preliminary or otherwise, expressed during the course of the inquiry will have no legal or other meaning or effect going forward."

The FCC's new Chairman, Ajit Pai, confirmed in a statement that the dropped inquiries are indeed part of a new direction for the agency, which will not make similar inquiries in the future.

"Today, the Wireless Telecommunications Bureau is closing its investigation into wireless carriers' free-data offerings," FCC Chairman Ajit Pai said in a statement.

"These free-data plans have proven to be popular among consumers, particularly low-income Americans, and have enhanced competition in the wireless marketplace. Going forward, the Federal Communications Commission will not focus on denying Americans free data. Instead, we will concentrate on expanding broadband deployment and encouraging innovative service offerings."