New York: If you are an employee in a large company and are thinking of using your work e-mail for job hunting or online dating, watch out.

A new survey finds that 41 percent of large companies (those with 20,000 or more employees) are employing staffers to read or otherwise analyse the contents of employees' outbound e-mail, technology website cnet.com reports.

In the study, which was commissioned by e-mail security provider Proofpoint and conducted by Forrester Research, 44 percent of the US companies surveyed said they investigated an e-mail leak of confidential data in the past year and 26 percent said they fired an employee for violating e-mail policies.

The companies also said they are worried about employees leaking company information on their blogs, message boards, and media-sharing sites like YouTube.

Eleven percent of the companies surveyed took disciplinary action against employees for improper use of blogs or message boards in the past year, and slightly more than that disciplined workers for social-network violations and for improper use of media-sharing sites.

And 14 percent of publicly traded companies investigated the leakage of material financial information, such as unannounced financial results, on blogs and message boards.