A federal prosecutor has won his fight to conceal e-mails he sent to his attorney over the government’s computers, contradicting a popular belief that employees have no expectation of privacy on work computers.

The U.S. District Court for the District of Columbia ruled on Thursday that Assistant U.S. Attorney Jonathan Tukel had a reasonable expectation of privacy in those e-mails because federal prosecutors were allowed to use work e-mail for personal matters. Therefore, Tukel’s messages to his private lawyer sent from work are covered by the attorney-client privilege and can remain confidential.