There's no need to wonder what, exactly, your employees are doing on social media – for a fee, you can track it in real time.

Mountain View, California-based software company Teneros has launched Social Sentry, which – for $2 to $8 per employee, depending on how much information you want – will track their every move on Facebook and Twitter, whether it's from their desktop computer or their own smartphone or anywhere else. It will also provide charts tracking exactly how much time employees are spending (wasting?) on social media. (By summer, the company will add YouTube, MySpace and LinkedIn to the list of social media Social Sentry tracks.) 

From the software's data sheet: "Social Sentry provides automatic detection of employee social networking presence, even if employees are using personal aliases for communication. It provides the ability to record, and archive, all of the monitored communications and content, whether for a single employee or a select set of employees based on risk assessment for legal and compliance issues."

Translation: If you choose, you can use the software to discover and monitor even information employees post using aliases – though only information they post publicly. You can also receive alerts when employees post specific words or terms – the company name, a product name, a competitor's name, or anything else you choose.

Half of small businesses have a social media policy – and some 90 percent try to enforce it, says a recent survey by security firm Webroot. To date, though, the enforcement mostly has consisted of sending out an email at least once a year reminding employees of the policy – something 46 percent of companies do, says Webroot.

If Social Sentry-style tracking sounds a bit Big Brother-ish, consider that a separate survey last year revealed 45 percent of companies are now using social networks to check out prospective employees and 22 percent say that they did not offer a job to potential hires because of what they've found on these networks . Teneros itself points out that 70 percent of white collar workers have Facebook accounts that they regularly access during work hours. What's more, huge companies such as Domino's Pizza have sustained major damage from hits their brand images took thanks to employees' behavior on social networks. (For some small business social media faux pas, click here.)

Of course, Social Sentry only tracks information that is already public, but as social media researcher Danah Boyd, a fellow at Harvard University's Berkman Center for Internet and Society, noted in her SXSW keynote earlier this month, even collecting seemingly public data quickly can feel like an invasion of privacy.

Legally speaking, you have a right to keep tabs on any public information related to an employee and to check on his or her productivity, says Nancy Flynn, executive director of the ePolicy Institute.

"You definitely want to take advantage of your legal right to monitor," she told The New York Times.  

What do you think? Do you already monitor your employees' behavior on social networks? How? What has the effect been?