The days of unlimited Internet end November 1.

That's when Comcast, the nation's largest broadband Internet provider, starts imposing a monthly data limit of 1 terabyte on subscribers nationwide. The company started testing this plan in a few cities earlier this year, and decided to roll it out in 28 states. Anyone exceeding the limit more than two months in a row can pony up $10 for blocks of 50 gigabytes, according to the company's website. That said, you'll never be charged an overage fee greater than $200, and Comcast is more than happy to let you pay an extra 50 bucks a month for unlimited data.

Internet service providers continue clamping down as people increasingly stream music and video. AT&T, for example, charges home broadband customers an extra $30 a month for unlimited data. Charter, now the second largest cable Internet company in US, remains the exception. The terms of its merger with Time Warner Cable bar it from imposing data limits.

Comcast claims 99 percent of its customers use less than 1TB per month, so this is no big deal. But some worry data limits give cable companies an advantage because they discourage people from using competitors like Dish Network’s Sling TV or on-demand services like Hulu and Netflix.

But Comcast says you can stream between 600 and 700 hours of high-def video each month under its 1TB cap. That works out to about 20 hours of video each day. Fair enough. But as 4K resolution televisions become more common and streaming becomes even more common, a household's need for bandwidth will only increase. Comcast says it could increase limits accordingly—after all, the limit started at 300GB in those test markets.

Others worry about the accuracy of Comcast's data meters. Last month, Ars Technica detailed one customer's inexplicable overage fees. Comcast charged the fellow hundreds of dollars despite their being no conceivable way he used as much as 3TB of data a month.

The company admitted its error, and credited the guy's account. But it stands by the accuracy of its meters, citing a report by the auditing company NetForce that its meters are on average 99 percent accurate.

But if a 1TB limit effects so few subscribers, why impose it? According to frequently cited paper about Comcast's congestion management system, the few people exceeding 1TB per month aren't harming anyone.

Comcast argues that fairness dictates that those who use more should pay more. The company offers a $5 per month discount to anyone who uses less than 5GB of data. But that seems meager compared to the cost of exceeding the 1TB limit. According to a Comcast spokesperson, the median Comcast subscriber uses 75GB of data each month. That means customers who use less than 5GB receive a $5 discount for using 1/15th that, but a customer who uses 15 times the median amount will be charged $30. You can decide whether that's fair.