A former administrative support worker at the U.S. embassy in London has been sentenced to a lengthy prison term after pleading guilty to a long-running cyber-stalking scheme in which he sought sexually explicit photographs of at least 200 women.

A judge in the U.S. city of Atlanta, Georgia sentenced 36-year-old Michael Ford this week to four years, nine months in prison after he pleaded guilty in December to 17 computer-related offenses.

U.S. prosecutors said that from early 2013 to mid-2015 Ford hacked into at least 450 email and social media accounts of the women, demanding they send him the photographs and other personal information.  He released some of the information the women sent him to their relatives and friends.

"He preyed on vulnerable victims, leaving them with indelible emotional scars," said Assistant Attorney General Leslie Caldwell.