Also, more employers are following perspective employees or existing workers by asking "friend" members of their company on Facebook, for example, with unrestricted rights to track the person, Matwyshyn says.

Seeking login credentials, though, is a different story, and one that some employers are averse to, says Dyke Debrie, of Kenexa, which provides software and job search tools for employers. "It kind of opens a whole Pandora's box," he says. Businesses are not allowed to use certain information including age, marital status, religious affiliation or sexual orientation to make employment decisions. Having access to a social media profile could reveal such information and Debrie says the businesses he works with don't even want to have access to the information because it can create questions about how it is used.

But some employers do want to glean into the social media lives of workers. The industries it is most common in, Matwyshyn says, are highly regulated ones, such as financial services, government and public positions or in which security clearances may be needed. Another area she's seen increased traction of social media monitoring is in customer-facing jobs and marketing positions. "From an employer's perspective, if they are putting an individual in a client or public-facing position, they way that candidate represents him or herself online could be an indication of the tone, professionalism and demeanor the individual may bring to the professional setting," she says.

Some companies feel they even have an obligation to monitor the social media habits of employees. If a financial broker has relationships with individuals or companies they are trading or advising clients of investing in, that can create a conflict of interest that the financial services firms may not only want to know about, but may be required to report and keep a record of. In response, Matwyshyn says, some financial services firms simply don't allow employees to engage in social media use.

Users that give up their login and password information, Matwyshyn says, are showing the disregard they have for personal privacy. It also demonstrates, Matwyshyn says, a power imbalance between employers and perspective employees. The more access to information job seekers give to their potential employers, they less control they have in crafting the image they want to portray to employers.