California Gov. Jerry Brown has signed the nation’s toughest net neutrality bill into law. The law will prohibit internet providers from blocking or throttling any legal apps and websites, and it will ban paid prioritization of content. The law also goes further than the since-overturned federal net neutrality rules by banning zero-rating — offering free data — of specific apps.

Several other states have taken action on net neutrality, but most chose to enact protections in a looser fashion that didn’t enforce it on all providers and wiggled around the Federal Communication Commission’s prohibition on state net neutrality laws. California, on the other hand, chose to just go for it, and it’s enacted a law that very clearly replicates and goes beyond the rules that the FCC instated in 2015 — and then revoked in 2017.

FCC chairman called the law “radical” and “illegal”

That means there’s certainly going to be a lawsuit. The first and most immediate question is whether the FCC’s ban on state-enacted net neutrality rules will hold up. The last time the FCC tried to undermine state laws — it wanted to allow cities to build their own broadband networks, even if states said they couldn’t — it lost in court. This is a similar situation, though the FCC has different reasoning for why the restriction of state laws is necessary.

Within half an hour of the signing being announced, The Washington Post reported that the Trump administration had already discussed suing California over the law and planned to file its lawsuit Monday morning in an attempt to block the net neutrality rules from going into place.

When the rules go into effect, likely next year, internet providers won’t be allowed to block or throttle content; they’ll have to allow all “nonharmful” devices to connect; offer paid fast lanes; charge interconnection fees; and to wiggle around these rules by, say, claiming a streaming TV service delivered over internet cables should be counted as TV delivery and not subject to regulations.

The law also takes an interesting approach to zero-rating. In 2015, the FCC left zero-rating open to be studied (and was heading in the direction of banning some behaviors), but California’s law has specific ideas about what works and what doesn’t: individual apps can’t be zero-rated, but entire categories of apps can be. So AT&T could let you stream all music apps without using up data, but it couldn’t just cut a deal with Spotify to offer free data.

The approach means that carriers wouldn’t have to get rid of some of their free data perks, but they would have to ensure they apply the perks evenly. In doing so, the downsides of zero-rating would be avoided. Net neutrality advocates had worried that allowing specific apps to be zero-rated would give them a competitive advantage over startups that couldn’t afford to pay or worse, that internet providers would favor their own apps over all competitors.

FCC chairman Ajit Pai has already declared his displeasure with the law. Earlier this month, he called it “egregious,” “radical, anti-consumer,” and “illegal.” Because the internet is an interstate service, he said, only the federal government should be allowed to regulate it.