NEW YORK ( MainStreet) — A backlash is brewing against companies that dig into potential employees' pasts on social media.

A survey from CareerBuilder.com shows 43% of U.S. companies have opted not to hire job candidates due to inappropriate behavior on sites such as Facebook or Twitter — a significant 9% rise from last year, and a clear sign that what you do online can cost you a job offer.

Half of hiring managers pulled a job offer over "provocative" photos found online, while 48% did the same after seeing information on a social media site about a job applicant drinking too much or using drugs.

"Employers are using all the tools available to them to ensure they make the correct hiring decision, and the use of social media continues to grow," says Rosemary Haefner, vice president of human resources at CareerBuilder. "For job-seekers it is essential to be aware of what information they're making available to employers, and to manage their online image.

"At the same time, hiring managers and human resources departments must carefully consider how to use information obtained from social media and whether it is relevant to a candidate's qualifications," Haefner adds.

It's that last thought that's vexing job applicants, most of whom want companies to stop using social media to make hiring decisions.

Data from North Carolina State University bears that sentiment out The university surveyed 175 participants in one study and 208 participants in a second to discern how potential employees felt about being judged on their social media activity.

The results show that the majority of employees downgrade their view of a company when they're told the firm vets applicants on their social media habits. It also increases the chances of a rejected job applicant to seek legal relief from companies that scope them out online.

"The recruiting and selection process is your first indication of how you'll be treated by a prospective employer," says Will Stoughton, a doctoral student at NC State and a main contributor to the study. "If elite job prospects feel their privacy has been compromised, it puts the hiring company at a competitive disadvantage."

In the first study, 66% said they considered a company that snooped on social media sites to be "less attractive" than one that didn't. In the second study, 60% of survey respondents said their privacy was violated after hearing an employer had monitored their social media activity. And 59% of respondents said they would be "more likely" to consult a lawyer over the issue.

Those numbers represent a warning shot across the bow of companies who use social media to screen job candidates.