Online gambling is booming across the U.S. and compliance experts caution that it creates opportunities for criminals to launder money or take part in other financial crimes.

The U.S. has seen states pile into legal online gambling with fervor, eager for potential tax revenue. Since 2018, when the U.S. Supreme Court struck down a ban on sports wagering, online sports betting has undergone a sharp increase.

“The more activity you have, the greater risk that you have,” said Alma Angotti, a former senior enforcer with the U.S. Treasury Department’s Financial Crimes Enforcement Network who now works as a partner at consulting firm Guidehouse Inc.