Comcast Corp one of the largest providers of home broadband in the nation has expanded consumer trials in 15 states that charges subscribers of Xfinity Internet extra fees when they stream a number of hours of video online or run through a huge amount of data.

These Comcast trials have reignited the debate over whether the telco and cable industries should be imposing these data caps on users of Internet.

Data caps are what punish heavy video streamers on Internet or on users of Hulu or Netflix, while protecting bundles from cable-TV, say critics.

However, Comcast as well as other providers of broadband say they charge the bandwidth hogs for burdens they are placing on the networks.

Comcast set its usage cap per month at 300 gigabytes. The average Xfinity customer at Comcast consumed around 40 gigabytes says the company.

Over the past two months, a trial started at Comcast of an option for charging subscribers of Xfinity Internet in Atlanta and South Florida an additional $30 to $35 per month for unlimited usage of data.

Comcast has experimented separately with charging its subscribers $10 per 50 gigabytes of data they use over 300 gigabytes per month.

The company based in Philadelphia describes the cap trials as being localized, but data on the website of Comcast shows it expanded the trials to over 1,300 zip codes across 15 states which is a substantial part of the cable TV Comcast franchise areas.

This past Wednesday, Comcast also added a number of small towns and cities in Louisiana, Virginia and Tennessee to its trial,

Mostly these areas with trials are in the Midwest and South. There are no cap trials for data in the Philadelphia area and non consumption limits technically exist on usage of Internet though that might change.

Comcast surveyed customers with the options and there was interest in the unlimited all you can use options that it rolled out this past September in Florida for $30 more each month and in Georgia for $35 more per month.