Don’t go streaming too much video or downloading too much content through your Sprint “unlimited” mobile broadband service, because it appears that there is a cap to your bandwidth and you’ll be charged for any excess. The cap has not yet been put in place, but it seems that Sprint is getting ready to cap your mobile data at five gigabytes a month. This rumor got its start at SprintUsers.com, a site that is not officially affiliate with Sprint-Nextel.

The report says that Sprint will be adjusting its terms of service on July 13th wherein they will install a 5GB cap on the so-called “unlimited” mobile broadband service. Sprint is certainly not the first wireless carrier to place a cap on an unlimited plan, following in the precedent set by Verizon Wireless and AT&T. The new terms of service is said to also limit the number of roaming minutes and data that a subscriber can use “before Sprint reserves the right to act by way of terminating service or reducing download speeds.”

So not only are they going to cap your data, they’re going to throttle your bandwidth too? Let’s hope this rumor doesn’t come to fruition.