The Electronic Frontier Foundation said the Alaska governor's e-mail account was hacked Thursday by someone posing as Palin to get a new password.
A legal analysis by Kurt Opsahl indicates a court would likely consider the incident a violation of the Stored Communications Act, but federal authorities might be hamstrung.
The U.S. Department of Justice's interpretation of the law means that any e-mails that Palin had already opened, but left on the Yahoo! Mail servers, would not be protected.
"As more and more people use Web mail like Yahoo!, Gmail, Hotmail and others, they also will naturally leave opened e-mail on the server," Opsahl wrote. "People should not have to sacrifice their privacy protections under the law when they do so."