The sender of the email threatened to go public with images captured from Wolf's webcam unless she would provide nude pictures of herself, Eimiller said — a crime commonly known as "sextortion."
Instead, Wolf went to authorities, and an investigation was launched in March.
A federal complaint filed on Sept. 17 and unsealed Thursday charges him with extortion but Eimiller said other charges are possible.
An FBI agent's affidavit, included in the complaint, contends that Abrahams used malicious software to remotely operate webcams to capture nude photos and videos of at least seven women as they changed clothes — some of whom he knew personally and others he found by hacking Facebook pages.
The agent alleged that Abrahams, when interviewed, acknowledged controlling 30 to 40 hacked computers and extorting some women.