It was going to be their secret -- a 13-year-old girl's portrait of her bare chest, snapped in a Hanover Township school bathroom on a cell phone camera borrowed from the intended recipient, a 14-year-old boy. But authorities say the boy shared the photo by sending it to his buddies via cell phone. That action triggered a police investigation, and although the girl willingly took the picture in September, the boy now stands accused of violating her privacy. Hanover Detective Earle Seely, who investigated, said yesterday the crime was committed when the boy pushed "send" and transmitted the image. The Sept. 28 incident should serve as an alarm to parents of teens, Seely said. "And not only about what they are doing with cell phones, but what they are doing in the privacy of their own bedrooms with computer Web cams," he said. "Parents need to wise up." If found guilty, the boy faces probation, community service and fines. The school district declined to discuss the case. The teens' parents also did not want to comment, police said. Legal experts and police say what happened at Hanover's Memorial Junior School is occurring more frequently. The problem is teens are technology savvy, but they don't have a real concept of personal privacy and are "extremely open when it comes to personal information. Just look at MySpace and Facebook Web sites," said Grayson Barber, a Princeton attorney and privacy expert. Barber even pointed to a recent high-profile Hollywood incident in which nude photos of Vanessa Hudgens, star of the Disney's "High School Musical," wound up on the Internet. Experts say while teens are used to posting personal information about who they are, their musical tastes and personal preferences, they can go overboard without realizing the consequences. In the Hanover case, the girl's use of the cell phone camera "was a dumb thing to do. As stupid as that may have been, she had a reasonable expectation of privacy," Barber said. Eugene O'Donnell, a professor of law and police studies at John Jay College of Criminal Justice, agreed. "This is not a case of boys will be boys," he said. "What happened was a violation of law." Rockaway Borough and Roxbury police have investigated claims of cell phone cameras capturing sex acts among teens. In Rockaway, Detective Kyle Schwarzmann said claims of improper cell phone camera use were at the heart of a six-month investigation last year into alleged off-campus sexual assaults involving students and recent graduates of Morris Knolls High School. One claim was made by a 16-year-old girl who said she was assaulted during a party at a Rockaway business, local police said. Three other girls made similar claims, saying they were sexually assaulted by a group of boys in Rockaway Township and Parsippany, police said. Investigators, however, were unable to confirm the allegations when no one would produce the videos, and no charges were filed. The line between what kids can and can't do with technology isn't always clear to children, Schwarzmann said. "Kids need to know what is legal and illegal, and that comes down to the parents," he said. "We can't give teens this type of technology without telling them what they can and can't do."