Microsoft urges FTC to crack down on Google

Heiner worried that Google may escape the FTC probe by only making voluntary commitments.

"Hopefully, Google will wake up to a New Year with a resolution to change its ways and start to conform with the antitrust laws. If not, then 2013 hopefully will be the year when antitrust enforcers display the resolve that Google continues to lack," he wrote.

Heiner argued that Google's failure to offer a fully featured YouTube app for Windows phones is an example of the company's anti-competitive behavior.

"This is an important issue because consumers value YouTube access on their phone: YouTube apps on the Android and Apple platforms were two of the most downloaded mobile applications in 2012, according to recent news reports," he wrote. "Yet Google still refuses to allow Windows Phone users to have the same access to YouTube that Android and Apple customers enjoy."

Heiner claimed that he learned that YouTube executives wanted to enable a fully featured app for Windows phones but that senior executives at Google told them to scrap the project.

In a statement, a Google spokesperson emphasized that Microsoft phone users can still access YouTube.

“Contrary to Microsoft’s claims, it’s easy for consumers to view YouTube videos on Windows phones. Windows phone users can access all the features of YouTube through our HTML5-based mobile website, including viewing high-quality video streams, finding favorite videos, seeing video ratings, and searching for video categories. In fact, we’ve worked with Microsoft for several years to help build a great YouTube experience on Windows phones," the company said.

—Updated at 5:26 p.m. to include Google's comment