Reports of companies asking job applicants for their logins and passwords to social networking sites like Facebook elicited a firestorm of criticism recently, prompting two U.S. senators to call for a government investigation, and legislators in several states to propose making the practice illegal.

The uproar started with an Associated Press article quoting job candidates who were asked to provide their logins and passwords for Facebook or other social networking sites by potential employers. The article cited several employers that ask for such information, including a Montana police department, which also asks for access to job candidates' e-mail accounts. In response, Sens. Ralph Blumenthal (D-Conn.) and Charles Schumer (D-N.Y.) sent letters to the Equal Employment Opportunity Commission and the Department of Justice asking them to investigate the legality of such requests.

But data from the Society of Human Resource Managers suggest that the practice is not widespread. In a 2011 survey of 541 SHRM members, just 18% said they use social networking sites as a tool for screening job candidates, while another 11% said they plan to use such sites in the future.