Comcast has begun testing data caps on its internet service in the U.S. Ars Technica points out that Comcast implemented a 300GB per month data cap in Nashville, Tennessee on August 1st, and will begin capping customers in Tucson, Arizona on October 1st. Tucson customers will have the option to sign up for either 300GB or 600GB of data per month.

Back in May, Comcast announced that it was ditching its 250GB data caps. The company announced that it would be exploring “improved data usage management approaches.” In fact, a 300GB per month flat cap (like Nashville) or a 300GB cap with options for higher-capped plans (Tucson) were both mentioned as options by Comcast at the time.

Under the Nashville plan, customers who exceed their 300GB monthly data allotment will be charged $10 for every subsequent 50GB of data they cross into. In order to ease customers into their new reality, Comcast will waive the first 3 incidences of overage that customers have during a 12-month period.

While any kind of data cap seems archaic for customers who have enjoyed the freedom of unlimited data in the past, 300GB at least is not prohibitive for the average customer. Still, for those who live their lives online – streaming their entertainment through Netflix and Hulu, playing online games with their friends, talking to their family through Skype, procrastinating on Reddit – that 300GB might not get them through one month. Some Canadians have it worse, though, with internet service providers that cap data at as little as 15GB. Just this week, Netflix Chief Content Officer Ted Sarandos called Canadian internet access “almost a human rights violation.”

Comcast is implementing these caps at the same time Google Fiber is going live in Kansas City. Google will even offer free broadband internet access to customers who pay a one-time build fee of $300.