• by Wendy Davis , Staff Writer @wendyndavis, April 15, 2016

Charter has promised that it won't impose data caps on broadband customers for at least three years, if regulators approve the company's proposed merger with Time Warner Cable and Bright House Network.

But that commitment obviously won't mean much in the long run if the company begins imposing data caps as soon as the three-year period expires.

This week, Roku made that point in a conversation with Federal Communications Commission officials.

The company says in a regulatory filing that it "described the importance of Charter not imposing data caps on broadband customers" during the conversation.

"As Roku explained, as more consumers adopt, or seek to adopt, streaming as their primary method of viewing video content on the television, data caps will have a more significant impact in 3-7 years after the transaction," the filing states.

Roku -- one of several services used by cord-cutters to stream online video -- also pressed the FCC to guarantee that in the future Charter will not devise broadband billing schemes that favor its own video services.

Roku's letter comes at a time when other broadband providers are experimenting with data caps, along with exemptions to them.

Comcast, for instance, recently rolled out Stream, a $15-a-month offering for broadband-only subscribers. People who purchase Stream can watch a roster of TV programs, which are delivered over broadband connections. All material accessed through Stream is exempt from Comcast's 300 GB-per-month data caps -- which have been rolled out to 15% of the company's customers.

Consumer advocates are asking the FCC to investigate whether Comcast is skirting net neutrality principles by giving consumers an incentive to use Stream instead of rival online video services, like Amazon Prime or Netflix.

(Comcast says Stream is a "cable service," and not an Internet offering. But consumer advocates say the company is playing a "regulatory shell game.")

Verizon also is exempting data from its own video service, go90.

And AT&T is cracking down on cord-cutters by charging them higher prices for unlimited broadband data. As of May 23, cord-cutters will have to pay an extra $30 a month for unlimited wireline data. People without pay-TV subscriptions who don't sign up for unlimited data will be charged an extra $10 for each 50 GB they consume over their monthly caps -- which range from 150 GB to 1 TB.

Roku isn't the only one to raise concerns about Charter's potential to thwart over-the-top services.

Dish says the deal would leave Charter in a position to undermine Sling TV, while HBO says Charter could hinder the stand-alone streaming service HBO Now.

Netflix, on the other hand, says it supports Charter's merger plans.

Regulators in New York and New Jersey have already approved Charter's merger plans. The FCC and Department of Justice haven't yet signed off on the deal.