– Last week, Sen. Al Franken was concerned about restrictions on music streaming services when trying to operate them on Apple devices, so he wrote to the U.S. Attorney General and the Federal Trade Commission.

The latest letter adds to a long list of efforts by the Democratic senator to pressure businesses or regulators to pay closer attention to privacy in the digital world.

This summer alone, Franken, D-Minn., has called attention to PayPal’s unavoidable robocalls, on which the online payments system has since changed its policy, Jimmy John’s noncompete clause for low-wage workers and now Apple’s potential anticompetitive practices.

These aren’t Franken’s biggest fights.

The senator was in steadfast opposition to the Comcast/Time Warner Cable merger and wrote a letter to government agencies expressing his concerns in February 2014. Sen. Amy Klobuchar, D-Minn., was also outspoken against the merger.

Franken feels like he scored a victory when the deal died this spring. He said it’s the big business battle he’s most proud of.

His efforts haven’t always been successful.

In 2010, he was outspoken with his concerns about the Comcast/NBC Universal Merger, which was ultimately approved in 2011.

However, Franken credits some conditions established during that fight with helping to prevent the 2014 Comcast/Time Warner merger.

His interest in telecommunications has motivated many of his other efforts, he said Friday.

“That happened pretty early [after being elected] and because of my familiarity with the industry, I had some concerns with the conglomeratization of telecom,” Franken said. “So I raised concerns there and so that started this long history of doing that kind of thing.”

Since taking office in 2009, Franken has also raised concerns about OnStar’s privacy policy, which was eventually changed, and a facial recognition app for Google Glass called NameTag, which delayed the app’s release.

More recently, the senator pushed back against Uber’s practice of tracking consumers’ locations. Uber, a popular transportation service, has since scaled back access to tracked locations, although Franken continues to have some concerns, he said.

He said the use of location data has been of high concern.

In January, Franken sent a second letter to Uber arguing that, “Americans have a fundamental right to privacy, which includes the right to know who is getting access to their personal geolocation.”

Franken’s doggedness on these issues come out of access (he’s the ranking member of the Judiciary Subcommittee on Privacy, Technology and the Law) and concern.

“That’s an area I’m interested in,” he said “Just concentration of power in all kinds of things but really in telecommunications.”