Lynn La/CNET

Sprint has stopped its data-throttling policy now that new Net neutrality rules are in place, the Wall Street Journal reported Thursday.

The carrier had been crimping data speeds for a certain percentage of users who consumed what was considered more than their fair share of data. But Sprint put the brakes on that policy last Friday, according to the Wall Street Journal, the same day the Federal Communications Commission's updated Net neutrality regulations went into effect.

On Wednesday, the FCC showed that it's taking Net neutrality seriously. The agency fined AT&T up to $100 million after accusing the carrier of misleading customers by throttling data on its unlimited mobile plans. By "falsely labeling" these plans as unlimited, AT&T violated its 2010 Open Internet Transparency Rule, the FCC said. The action is the first time the FCC has charged a company for violating Net neutrality rules.

Sprint acknowledged the halt to its data throttling in a statement sent to CNET:

For less than a year, Sprint used a network management practice that applied only at the level of individual congested cell sites, and only for as long as congestion existed. At such sites, we temporarily allocated resources away from the top 5 percent of heaviest users and to the 95 percent of users with normal usage, to try to allocate the effects of congestion more fairly. Once congestion at the site passed, the limitation automatically ended. Upon review, and to ensure that our practices are consistent with the FCC's net neutrality rules, we determined that the network management technique was not needed to ensure a quality experience for the majority of customers.

The carrier told the Journal it believes its policy would have been allowed under the new rules but said it dropped the policy just in case. Sprint also said it had retained the right to prioritize traffic based on a customer's plan, though it had never done so and had decided that such a policy is no longer necessary.

Often employed by wireless carriers to control network congestion, data throttling is the process of slowing down cellular speeds for mobile users who chew up the greatest amount of data. For example, those who have 4G plans may see their speeds throttled to 3G after going beyond a certain threshhold of data for the month. The carriers have defended the practice as a way of clamping down on data hogs. But critics have charged that data throttling should be prohibited, especially under wireless plans that are advertised as "unlimited."

Those punished for using up too much data are also left in the dark as to how much data is too much. Instead of imposing a specific limit, the carriers typically throttle speeds on the people who end up in the top percentile of data hogs, whatever that number may be. That means people have no way of knowing if and when their speeds may be throttled.

Last week's FCC ruling sided with the critics of data throttling.

The new rules reclassify broadband as a public utility for the first time ever and prevent broadband providers from slowing down or blocking Internet traffic. The rules mean that data throttling would be considered a violation of FCC policy, putting pressure on the wireless carriers to put an end to the practice.

In addition, the regulations prevent Internet service providers from offering paid priority services that would let them charge more money to content providers in order to gain more speed and bandwidth at times when the network is congested. So the act of prioritizing traffic goes against the very nature of net neutrality.

But the fight over Net neutrality is still simmering. The FCC is facing several lawsuits challenging its new rules.