Mack was arrested Friday for her role in the notorious cult Nxivm, where prosecutors allege she recruited "slaves" to have sex with the group's leader.
Nxivm leaders are accused of trying to undermine potential witnesses by registering websites in their names and threatening to reveal damaging information about them.
"When you or I were kids, we would pull out the Sharpie and try to get celebrities to sign something," Cameo CEO Steven Galanis said. "Today everyone wants to take a selfie with them."