Some of Aguilera's photos appeared online after Chaney sent an email from the account of her stylist, Simone Harouche, to Aguilera asking the singer for scantily clad photographs, prosecutors said.
Chaney forwarded many of the photographs to two gossip websites and another hacker, but there wasn't evidence he profited from his scheme, authorities said.
For the two women, who were only identified in court papers by their initials, their encounters with Chaney went from friendly to frightening.
One of the women, identified by the initials T.B., said she first met Chaney online in 1999 when she was 13 years old. She began talking with a girl named "Jessica" that later turned out to actually be Chaney.
Chaney figured out his victims' email passwords and security questions and set a feature to forward a copy of every email they received to an account he controlled.
The woman said that in February 2009 her friends contacted her and let her know that several nude photos of her were uploaded to a public gallery. A year later, Chaney sent a link to a photo-sharing website he created and had her nude pictures sent to her father.
She said she spends several hours a week monitoring the Internet for her personal information and breaks into a sweat whenever she receives a Google alert email notifying her that her name has been mentioned online.
In her letter to U.S. District Judge S. James Otero, she said she thinks Chaney won't stop and she still feels like he has control over her reputation, relationships and career.
Chaney was arrested in October 2011 as part of a yearlong investigation of celebrity hacking that authorities dubbed "Operation Hackerazzi." Chaney's computer hard drive contained numerous private celebrity photos and a document that compiled their extensive personal data, according to a search warrant.