This morning, the Federal Trade Commission filed a lawsuit against Volkswagen Group of America, charging that it “deceived customers with the advertising campaign it used to promote its supposedly ‘clean diesel’ VWs and Audis,” according to the FTC press release. As I’m sure you recall, these are the vehicles that were caught cheating on emissions tests in October 2015.

The lawsuit seeks damages for any Americans who bought or leased one of the Volkswagens or Audis from 2008 to 2015. It also asks that Volkswagen not deceive consumers anymore, a lesson it seems they’ve learned in the past six months.

The FTC says that Volkswagen advertised its diesel vehicles as being low-emissions, environmentally friendly cars that would retain their resale value. More than half a million Americans thought that sounded pretty good and purchased or leased diesel VWs and Audis over those seven years.

In particular, the lawsuit notes that these cars were advertised as being “50-state compliant,” meaning that they would pass emissions tests everywhere in the country, even in the toughest states, like California. And they certainly did pass those tests, but not honestly.

When the cars detected that they were being tested for emissions in the lab, which is the usual way they’re tested, a few lines of code changed the way the engine behaved to emit fewer pollutants. When cars were driven on the road, the engine would optimize for performance and sacrifice emissions. When they were tested on the road using probes in the tailpipe, nitrous oxide emissions were as much as 35 times the standard, as discovered by the International Council on Clean Transportation with help from West Virginia University’s Center for Alternative Fuels, Engines and Emissions. The lawsuit charges that this was an unfair practice.

You probably know if you’re one of the consumers affected, but in case you’re unsure, the lawsuit covers 2009 through 2015 Volkswagen TDI Jettas, Passats, and Touaregs, plus all Audi TDI vehicles for those years. The average price of these vehicles was $28,000, and the FTC is suing for compensation for anyone who purchased one of these vehicles at any price.