Federal agents arrested a State Department employee flying out of Atlanta this week and charged him with running a massive “sextortion” scam claiming he stole sexually explicit photos of young women from their Internet accounts and then blackmailed them for more sexual photos and videos.

Michael C. Ford, a staffer at the American embassy in London who was visiting his parents in Alpharetta, is suspected of victimizing hundreds of young women across the nation by hacking their accounts from his State Department computer. He wanted to humiliate, torment and intimidate the women— often university sorority sisters — by threatening to post the photos online with their name and address, a prosecutor said.

He is accused of emailing the photos to at least one woman’s parents and brother, said Senior Trial Attorney Mona Sedky of the Justice Department’s Criminal Division’s Computer Crime and Intellectual Property Section. She flew in from Washington D.C. to oppose bond for Ford at a hearing Thursday in federal court in Atlanta. The women fear Ford would continue harassing them, she said.

She contended it was cyber crime of such magnitude that a magistrate should take the unusual step in federal court of not setting a bond. Magistrate E. Clayton Scofield, however, rebuffed the contention Ford posed such a continual threat to the emotional well-being of young women that he should remain locked up until his trial or plea.

He set a $50,000 bond for Ford and ordered house arrest at a house he owns in Dunwoody. Scofield prohibited the home, including cars in the garage, from having any computers or Internet access.

Ford, who has lived in Great Britain since 2005, faces multiple charges including cyber-stalking and making interstate threats. “Sextortion,” is a growing crime, experts say, in which often young women are turned into targets for financial blackmail or sexual gratification because of sexually explicit photos of themselves they kept in Internet accounts.

Ford is not accused of extorting money. Sedky described the man, who sat shackled in an orange jumpsuit Thursday, as a predator who derived pleasure from toying with his victims and coercing more photos and videos from them.

“He targeted women at U.S. colleges and universities and was looking for women who were members of sororities … and aspiring models,” Sedky said. “He is just relentless.”

The case first came to attention of the FBI after an 18-year-old in Kentucky and 22-year-old in Illinois, complained their Internet accounts had been hacked earlier this year and they were targeted for extortion.

In April, Eric J. Kasik, of the Department of State Diplomatic Security Service, said a federal agent asked him for help in tracking down someone who might have been using a State Department computer to cyber-stalk a woman in Kentucky, according to a federal arrest warrant.

Ford, 35, is accused of getting the women’s email passwords through “phishing” expeditions. The warrant said he would send emails masked as from coming from an official Google account that threatened to shut down the account unless the women verified their information and provided a password. He would then use the password to help hack into their Internet accounts where they stored photographs, the warrant said.

Sedky said one of the email accounts employed by Ford to deliver the explicit photos to the victims was named “LookatwhatIhave666.”

A search of Ford’s computer at the London Embassy turned up a spreadsheet of 262 email addresses, Sedky said. Some were associated with schools such as Ball State University and the University of Michigan.

“I believe that the account holders listed on the spreadsheet are all victims of Ford’s criminal activity,” Kasik wrote in the May 15 affidavit for the warrant.

Ford is accused of extortion to try to force his victims into providing more compromising video for him with their cellphones, Kasik said.

He “apparently hacked into and stole compromising photographs from the online accounts belonging Jane Doe One,” Kasik wrote in the affidavit. “He then demanded that Jane Doe One take videos of other girls” and “sexy girls” who were undressing in changing rooms at pools, gyms, and clothing stores, and then give the videos to him.”

Ford, a St Pius X Catholic High School graduate grew up in Alpharetta. His lawyers said he married his childhood sweetheart after attending Valdosta State University.

The couple has a 15-month-old child, according to his lawyer Benjamin Alper.

Ford was arrested Sunday when planning to fly back to London first-class with his family, Sedky said.

She said he made a three hour confession after agents arrested him. He said he had been unable to stop the stalking.

Sedky noted Ford apparently spent hours cyber-stalking at his embassy computer despite its warning from the State Department it was monitored. State Department security, however, apparently never detected the stalking.

“He was very brazen,” she said.