The Brooklyn district attorney’s office has broken up what it’s calling a “billion-dollar sports gambling ring” that used password-protected websites and a Costa Rica-based ‘wire room.’

On Thursday, Brooklyn DA Ken Thompson announced a 57-count indictment against four individuals – including the alleged ringleader, California resident Gordon Mitchnick – who are facing up to 25 years in prison if convicted of the main charge of enterprise corruption.

Thompson said the ring operated via toll-free phone numbers and multiple ‘pay per head’ websites, including wagerabc.com, thewagerspot.com and hustler247.ag, through which customers could manage their wagering activity but all financial transactions were processed in person like traditional credit betting operations.

The ring had a customer list that numbered in the thousands, and Thompson said the sites handled $927m worth of wagers during the 2015 NFL season. Mitchnick utilized a variety of methods of laundering the ring’s betting proceeds, including buying over 20 houses.