(Joan Goodchild, NetworkWorld) A new survey finds more organizations are dealing with data loss and security breaches due to employee use of social media sites. Email security firm Proofpoint polled 261 IT decision makers at organizations with more than 1000 employees. Respondents were asked about the frequency of data loss events in the past 12 months, as well as their concerns, priorities and policies related to email, the Web, social media and other sources of data loss risk.

The survey found 20% of companies polled had investigated the exposure of confidential, sensitive or private information via a post to a social networking site. In many instances, the events have been severe enough to lead to job loss or disciplinary action, with 7% of companies reporting termination of an employee for social networking policy violations. Another 20% disciplined an employee for not following social networking policy.

Social networking sites such as Facebook and LinkedIn were cited by 53% of respondents as a high concern when it comes to the risk of information leakage. However, not all companies are concerned enough to make the sites off limits. Only 53% explicitly prohibit the use of Facebook and 31% explicitly prohibit use of LinkedIn. Microblogging service Twitter was mentioned by 17% of companies as a source of investigation due to the exposure of confidential, sensitive or private information. Additionally, 51% said they are highly concerned about the risk of information leakage on Twitter.