The Supreme Court on Wednesday refused to stop federal investigations into the private lives of people who want to work at government installations — even those who don't have security clearances and don't work on secret projects.

The high court turned away challenges to background checks of low-risk employees at NASA's Jet Propulsion Laboratory in California, despite claims from those federal contractors that the investigations were unconstitutional because they invaded their privacy.

"We reject the argument that the government, when it requests job-related personal information in an employment background check, has a constitutional burden to demonstrate that its questions are 'necessary' or the least restrictive means of furthering its interests," Justice Samuel Alito said.

Employees said the agency was invading their privacy by requiring investigations that looked into their medical records and asked friends about their finances and sex lives. If the workers didn't agree to the checks and fill out questionnaires on Standard Form 85 (SF-85) and Form 42, they were to be fired.