If you keep getting passed over for jobs, you might want to check your online image.

More employers than ever are using social media to find additional information on potential candidates, and they’re not too impressed with what they see, according to a new study from CareerBuilder.

Overall, 43 percent of employers use social networking sites to research job candidates, up from 39 percent last year and 36 percent in 2012. Additionally, 12 percent of employers plan to start researching candidates on social media, though they don’t yet do so.

Among those who already use social media as part of their hiring process, 51 percent have found content that convinced them to reject a candidate, up from 43 percent last year and 34 percent in 2012.

Employers pass on candidates because of what they see on their social networking sites for a number of reasons. The most common include:

  • Job candidate posted provocative or inappropriate photographs or information.
  • Job candidate posted information about drinking or using drugs.
  • Job candidates bad-mouthed their previous companies or fellow employees.
  • Job candidate had poor communication skills.
  • Job candidate made discriminatory comments related to race, gender, religion, etc.
  • Job candidate lied about his or her about qualifications.
  • Job candidate shared confidential information from previous employers.
  • Job candidate was linked to criminal behavior.
  • Job candidate’s screen name was unprofessional.

And employers aren’t limiting themselves to social networks when researching a candidate’s online image. The study discovered that 45 percent of employers use search engines such as Google to research potential job candidates, with 12 percent reviewing a potential job candidate’s posts or comments on Glassdoor.com, Yelp.com or other ratings sites.

Rosemary Haefner, vice president of human resources at CareerBuilder, said job seekers need to remember that employers can find much of what these applicants post to the Internet, and in some cases what others post about them. Workers should also realize how those posts can affect their chances of getting hired down the road.

“Job seekers need to stay vigilant, and pay attention to privacy updates from all of their social networking accounts so they know what information is out there for others to see,” Haefner said. “Take control of your Web presence by limiting who can post to your profile and monitoring posts you’ve been tagged in.”

While social media can give employers plenty of reasons to reconsider a candidate, it can also help applicants. The research revealed that one-third of employers who research candidates on social networking sites said they’ve found content that made them more likely to hire a candidate. In addition, nearly a quarter found content that directly led to them hiring the candidate, up from 19 percent last year.

Read more: Unliked: How Facebook Wrecks Your Job Search