Entrepreneur and cryptocurrency investor Michael Terpin sued AT&T on Wednesday, claiming that it should be held liable for fraudsters who hijacked his phone number and stole about $24 million worth of cryptocurrency.

The suit, filed in U.S. District Court for the Central District of California by a team at Greenberg Glusker Fields Claman & Machtinger led by Pierce O’Donnell, seeks to recover Terpin’s losses as well as $200 million in punitive damages. He claims that AT&T knew that employees at its retail stores could override security measures meant to protect high-profile customers or those who were likely targets of fraud.