If you happen to be a Sprint wireless subscriber with a heavy data appetite and live in a congested area, things are about to go from bad to worse on the download front. That's because the carrier has started informing customers that as of June 1, they may start managing (throttling) network resources in congested areas for customers within the top five percent of data users.

Sprint doesn't say how slow speeds will get when throttled but according to a FAQ on their website, customers may experience slower-than-normal data speeds. It's designed to enable the majority of users to have access to a fair share of the network at peak times when congestion usually occurs.

While Sprint doesn't specifically outline what it constitutes as being among the top five percent of data users, current customers who typically use 5GB or more in a given month are likely to fall into the category. To get an estimate of approximately how much data certain activities use, subscribers are encouraged to check out Sprint's data calculator.

The top five percent of data users will be determined on a monthly basis, we're told. If a user is identified as falling within the top five percent, they will be subject to throttling for the following month.

It's worth pointing out that congestion-based throttling will also affect pre-paid customers on Boost and Virgin Mobile USA. Of course, most pre-paid customers are already subjected to throttling once they pass a preset data threshold.