Of course, employers have good reason to want to know whether employees are stealing corporate secrets, sending out sexually harassing emails or just goofing off on the job. But experts say many companies are still trying to figure out a balance between monitoring wrongdoing and just plain snooping.
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"In the information economy we have incredible new ways to gather data, many of which are very novel, very new, and we're not entirely clear on what the standards are or should be," said Trevor Hughes, chief executive of the International Association of Privacy Professionals, a trade group whose membership includes big corporations such as Google, Microsoft and American Express.
Hughes said that's been made even more complicated because the line between work and home increasingly is blurred. For example, many employees might use their personal smart phone to send a work-related email at night, and then use their work computer to send a personal email during the work day.
Employers generally have the right to monitor employee emails and other online activity that happens at work, or even on a company cell phone or corporate network, said Lothar Determann, a partner at Baker & McKenzie in Palo Alto, Calif., and author of "Determann's Field Guide to International Data Privacy Law Compliance." But they can only do so if they make clear to their employees that workers should have no expectation of privacy.
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U.S. laws generally give employers much broader rights to monitor employee activity than in European countries, Determann said. That is raising complications for companies that operate in several countries.
But even in the U.S., Determann said companies risk running into trouble if they overstep their bounds. For example, an employer could use a keystroke tracker to get your password to that personal email account you checked at work, and then use that password to check your account later. But he would recommend against a client doing that because it could violate the rights of the email operator.
Many companies also are grappling with the thorny issue of how much control they have over the work activity people do on their personal cell phone or other device.
"It's an unsettled area right now," said Robert Sprague, an associate professor at the University of Wyoming College of Business and an expert on privacy and technology.
The idea of asking employees or job candidates for access to personal social media accounts such as Facebook also has caused widespread outcry, and lawmakers in several states have moved to ban such practices.
Employees may be generally aware that their employer could monitor their activities, but Maltby said many people assume that with all that data flying around their individual correspondence won't be tracked. In reality, he said, people are nosy and anyone from the IT guy to your boss may be tempted to peruse your activities.
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To maintain privacy, he recommends sending any personal emails or other correspondence from a personal cell phone or device that isn't connected to your corporate network.
Others say that it's generally fine to send a few innocuous personal emails at work, or check a personal website now and again. But that rant about the CEO that you're tempted to send your co-worker? Probably not a good idea.
"If you don't want your boss to read it, then don't send the email," Determann said.
— By Allison Linn, Today