More employers are turning to social networking sites to find additional information on potential candidates — and they’re not entirely impressed with what they’re seeing, according to a new survey from CareerBuilder. The survey found 51 percent of employers who research job candidates on social media found content that caused them to not hire the candidate, up from 43 percent last year and 34 percent in 2012.

According to the survey, 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 don’t currently research candidates on social media, but plan to start.

Employers aren’t limiting themselves to social networks when it comes to researching candidates’ Web presences. Forty-five percent of employers use search engines such as Google to research potential job candidates, with 20 percent saying they do so frequently or always. Additionally, 12 percent of employers say they’ve reviewed a potential job candidate’s posts or comments on Glassdoor.com, Yelp.com or other ratings sites.

The five most common reasons to pass on a candidate included:

1. Job candidate posted provocative or inappropriate photographs or information, 46 percent
2. Job candidate posted information about them drinking or using drugs, 41 percent
3. Job candidates bad-mouthed their previous company or fellow employee, 36 percent
4. Job candidate had poor communication skills, 32 percent
5. Job candidate had discriminatory comments related to race, gender, religion, etc., 28 percent

The five most common reasons employers hired a candidate based on their social networking presence included:

1. Got a good feel for the job candidate’s personality, could see a good fit within the company culture, 46 percent
2. Job candidate’s background information supported their professional qualifications for the job, 45 percent
3. Job candidate’s site conveyed a professional image, 43 percent
4. Job candidate was well-rounded, showed a wide range of interests, 40 percent
5. Job candidate had great communication skills, 40 percent

The survey was conducted online within the U.S. by Harris Poll on behalf of CareerBuilder among 2,138 hiring managers and human resource professionals and 3,022 adult workers between Feb. 10 and March 4, 2014.