Maryland resident Ha San Yu was sentenced to more than 17 years in prison for “using fear, violence and threats of violence to extort Korean businesses operating in Annandale,” according to a news release from the U.S Attorney’s Office for the Eastern District of Virginia.

Yu, 44, is the founder of the “Korean Night Breeders” and used the gang to extort restaurants, young women hired to flirt with men, and taxi businesses, the news release said. Yu, also known as “Thunder” or “Bungay,” pleaded guilty to conspiracy to commit extortion in November and has agreed to pay more than $98,000 in restitution to victims.

“Dressed in black suits, which became their uniform, Yu and the Korean Night Breeders would surround their victims and threaten violence unless they paid a ‘tax’ or ‘protection’ money,” according to the news release. “From one victim alone, the Korean Night Breeders extorted more than $30,000. Various restaurants in Annandale either paid extortion or provided free food and drink to the Korean Night Breeders.”

Three of Yu’s co-conspirators are scheduled for sentencing Feb. 22.