Federal protection for net neutrality will soon end. The Federal Communications Commission’s new regulations, which abandon rules against blocking, throttling, or otherwise discriminating against lawful content, were published in the Federal Register Thursday, though it's not yet clear when most of the changes will take effect 1.

As the FCC withdraws from protecting net neutrality, states are taking up the fight. Five governors have issued executive orders banning state agencies from doing business with broadband providers that don't promise to protect net neutrality, and at least 26 state legislatures are considering net neutrality rules as well.

Assuming the rules survive legal challenges, the big question is how states will ensure carriers keep their promises. "Blocking is straightforward," says Ernesto Falcon, a lawyer with the Electronic Frontier Foundation. "Throttling is much more complicated."

There are many reasons why one app might be slower than another. The app makers may have skimped on infrastructure. Or the app might be temporarily overloaded. Or maybe someone else in your house, using the same WiFi connection, started hogging your bandwidth as you opened the app.

None of the five governors’ offices responded to our questions about how they plan to monitor broadband providers for net neutrality violations. Falcon says states will need hard data, and engineers to review that data, to identify throttling, discrimination, or prioritization. That's part of the motivation behind Northeastern University's Wehe project, which helps users check to see how neutral their connections are.

Wehe offers apps for both Android and iOS that test the speeds of several popular apps, including Netflix, YouTube, Spotify, and Skype, by downloading data cloned from those apps and sending that data from Wehe's servers. Then the app downloads random data from the same servers and compares the data-transfer rates. Wehe tracks how quickly the cloned data downloads, compared with the random data. The apps can test both mobile connections and, via WiFi, home broadband connections.

By gathering data from many people using their devices in different places and at different times, Wehe can get a better sense than any individual user of whether certain apps or services are treated differently than others. Wehe’s apps have been downloaded more than 150,000 times, and at least 100,000 people have used them.

Wehe project lead David Choffnes says the group hopes to release anonymized data sets this spring, so that regulators, users, watchdog groups, and broadband providers themselves can analyze the data. The team is already working with the French telecommunications regulator Arcep and has a contract with Verizon to provide measurements of video-streaming quality over cellular networks.

Choffnes says the team hasn't found any cable or DSL providers like Comcast or Charter throttling video. But it has noticed that AT&T, T-Mobile, and Verizon all take take steps to slow video content on their mobile networks. All three disclose the practice and both AT&T and T-Mobile allow you to opt out of the speed constraints. That’s important under the FCC’s new regime, which requires only disclosure. But it hasn't always been clear what the companies’ disclosures actually mean.

Since 2015, for example, T-Mobile’s "Binge On" feature has allowed customers to watch unlimited amounts of video from the company's partners, including Netflix and Hulu, without those video streams counting against their data limits. When it launched, T-Mobile specified that only DVD-quality video, not high-definition video, would be exempted from data limits. But it didn’t explain that Binge On also slowed all video connections, including those of sites that didn't partner with T-Mobile and weren't exempt from data limits.