(NewsNation) — American Airlines is suing a travel company that makes it easier for people to save money on flights with a clever, but risky, travel hack.

American sued Skiplagged Inc. in federal court in Fort Worth, Texas, this week, accusing the website of deception. It threatened to cancel every ticket that Skiplagged has sold.

In the lawsuit, American accused Skiplagged of tricking consumers into believing they can tap “some kind of secret ‘loophole.’” American said the website poses as an ordinary consumer to buy tickets, and warns its customers not to tip off the airline about the arrangement.

The practice within the travel industry is called “hidden city” fares, or “skiplagging.”

It works like this:

When trying to book a flight to a desired destination, travelers look to buy the cheapest airfare — even if that means booking a flight to a city that isn’t their final destination.

Last month, American booted a 17-year-old from a flight and banned him for three years when he tried to use the tactic to fly from Gainesville, Florida, to Charlotte, North Carolina, on a ticket that listed New York City as his destination. For the teen, that was cheaper than booking a flight directly to Charlotte.

NewsNation writer Devan Markham and The Associated Press contributed to this report.