From the Air Force to the Treasury Department, government agencies are using either "Web bugs" or permanent cookies to monitor their visitors' behavior, even though federal law restricts the practice.

"We were not aware of the cookies set to expire in 2016," a Pentagon representative said Wednesday. "All of the cookies we had set with WebTrends were to be strictly (temporary) cookies, and we are taking immediate action." WebTrends is a commercial Web-monitoring service.