Although Verizon says its FiOS Internet service "doesn't cap usage in any way," one customer who has been using 7TB monthly for several months in a row got a letter warning him that his broadband will be disconnected unless he reins in his "excessive usage."

"If this excessive usage continues past May 31, 2015 on your FiOS Internet account, your service will be disconnected on June 15, 2015," Verizon wrote to the subscriber.

The subscriber pays $315 a month for Verizon's 500Mbps plan, according to DSLReports

"If you break it down it accounts to a single ~24 hours of usage at the full 500Mbps, or 20Mbps for a continuous 30 days," the user told DSLReports. "My usage is irregular and usually spikes up and down and sometimes the connection will sit idle for a day or two at a time. It makes me curious why 500Mbps is even offered if just using a whopping four percent of that connection is prohibited."

The FiOS customer also said his prodigious Internet usage is "largely thanks to volunteer web crawling projects like Seti@Home," which shouldn't violate Verizon's rules.

While Verizon's terms of service for residential users say they may not "host any type of server" and may not "generate excessive amounts of e-mail or other Internet traffic," it appears this user was targeted solely because of the amount of usage rather than the type. The terms of service do not define what counts as "excessive."

Verizon's letter to the subscriber does not pinpoint any specific violation other than "excessive usage," but it recommends "that you check to see if your computer or other device has any peer-to-peer or file sharing software on it. You should also contact any others who have access to your Internet service and discuss the notification with them. If you have a wireless router, Verizon recommends using the strongest network encryption compatible with your network devices to prevent others from accessing your connection without your permission."

If the subscriber can't decrease usage, he should purchase a business-class plan, the letter said.

In 2013, we wrote about one FiOS customer who got a warning because he was using more than 50TB per month. But in that case, the customer was clearly violating the terms of service by running a rack full of servers.

Generally, using 4TB a month will bring a warning from Verizon, according to DSLReports.

We asked Verizon if it is enforcing a specific data limit even though it says FiOS is uncapped, and what the limit is. Verizon didn't answer clearly, but it appears the multi-terabyte limits are used to make a distinction between business and residential services. Verizon's statement to Ars said:

A small number of FiOS Internet residential service customers are consuming volumes of data every month at levels that far exceed the monthly residential customer average for their service. To put this in context, FiOS Internet residential customers we have contacted would have to watch at least 6,660 movies per month or 222 movies per day to consume the amount of data they are using per month. We have asked these customers who are using their home Internet service at these volumes to (1) curb their usage; or (2) consider changing to a business-class service that is appropriate for their data usage. Verizon’s broadband networks provide a remarkably reliable and robust home Internet experience. The terms of service help ensure a consistent experience for every customer.

While Verizon's claim to offer uncapped Internet service isn't strictly accurate, the limits are a lot more forgiving than Comcast's.