States are bound by the Eighth Amendment's prohibition against excessive fines and fees when they seek to seize property or other assets from individuals charged or convicted of a crime, the U.S. Supreme Court ruled unanimously on Wednesday.

It's a decision that hands a major victory to critics of civil asset forfeiture, and it opens another avenue to legal challenges against that widely used (and often abused) practice by which states and local governments can seize cars, cash, homes, and pretty much anything else that is suspected of being used to commit a crime.

The case before the Supreme Court, Timbs v. Indiana, involved the seizure of a $42,000 Land Rover SUV from Tyson Timbs, who was arrested in 2015 for selling heroin to undercover police officers. He pleaded guilty to his crimes and was sentenced to one year of house arrest and five years of probation. On top of that, the state of Indiana seized his 2012 Land Rover—which he had purchased with money received from his late father's life insurance payout, not with the proceeds of drug sales—on the ground that it had been used to commit a crime.

Timbs challenged that seizure, arguing that taking his vehicle amounted to an additional fine on top of the sentence he had already received. The Indiana Supreme Court rejected that argument, solely because the U.S. Supreme Court had never explicitly stated that the Eighth Amendment applied to the states.

On Wednesday, the high court did exactly that.

"For good reason, the protection against excessive fines has been a constant shield throughout Anglo-American history," wrote Justice Ruth Bader Ginsburg in the opinion. "Excessive fines can be used, for example, to retaliate against or chill the speech of political enemies," she wrote, or can become sources of revenue disconnected from the criminal justice system.

Indeed, some local governments do use fines and fees as a means to raise revenue, and that has created a perverse incentive to target residents. After the 2014 shooting of Michael Brown in Ferguson, Missouri, a federal investigation into the city government found that 20 percent of its general fund came from criminal fines. And Ferguson is not alone in relying heavily on revenue from fines. Making clear that the Eighth Amendment applies to the states will make it far easier to challenge unreasonable fines and fees—including not just asset forfeiture cases, but also situations where local governments hit homeowners with massive civil penalties for offenses such as unapproved paint jobs or Halloween decorations.

Some of those cases are already getting teed up. As C.J. Ciaramella wrote in this month's issue of Reason, a federal class action civil rights lawsuit challenging the aggressive asset forfeiture program in Wayne County, Michigan, that was filed in December argues that the county's seizure of a 2015 Kia Soul after the owner was caught with $10 of marijuana should be deemed an excessive fine.

More broadly, Timbs is a good reminder of how ridiculous the argument in favor of civil asset forfeiture really is. During oral arguments in November, Indiana's solicitor general got boxed into a corner by Justice Stephen Breyer, who managed to twist the government's lawyer into arguing that Indiana should be allowed to seize vehicles for as small an offense as driving 5 mph over the speed limit, which literally elicited laughter in the courtroom.

After Wednesday's ruling, there's a better chance that more civil asset forfeiture cases will be laughed right out of court for being what they obviously are: unconstitutional, excessive punishments that don't fit the crime.