Senate Judiciary Committee Chairman Chuck Grassley (R-Iowa) joined several other high-ranking colleagues on Monday in hitting Federal Communications Commission Chairman Tom Wheeler’s plan to open up the market for television boxes.

“I support the goal of greater competition and innovation in the marketplace for how consumers are able to access and watch video programming,” Grassley said in a letter.

{mosads}“However, I am concerned that this proposed rule making would replace marketplace solutions with greater government regulation,” he said. “Further, there are significant concerns as to how the FCC’s proposal affects important consumer privacy and copyright interests.”

An FCC spokesperson said that the agency had received and was reviewing the letter.

Wheeler’s proposal would require video providers like Comcast or Charter Communications to open up their video feeds to anyone who wanted to make a box for consumers to purchase. Reforms are backed by Google and TiVo, who stand to make money from their own boxes.

But the video industry says that, among other critiques, the proposal would chip away at privacy and copyright protections that they say are afforded through the current system. They say that tech companies looking to manufacturer set top boxes will not have to comply with the same privacy rules that apply to video providers.

The stakes are potentially high for existing video providers. Most consumers rent their set-top box, generating billions in revenue for the industry every year.

Grassley is one of several critics of the plan in the upper chamber. Senate Majority Whip John Cornyn (R-Texas) recently expressed worries about the proposal, as has Senate Commerce Committee ranking member Bill Nelson (D-Fla.). Sen. Orrin Hatch (R-Utah), a senior lawmaker on Grassley’s committee, last week also wrote a letter with concerns about the plan.