Big Brother may or may not be watching you, but there is an increasing likelihood that prospective employers are — at least when it comes to your social media persona.

With graduation season upon us, many former students are posting their grad party exploits, much to the amusement of their friends on Facebook and other platforms. Many are also demonstrating their social media prowess with political rants, complaints about bosses or intimate Instagrams.

But these posts can have serious ramifications for job searches once the parties are over and it’s time to pound the pavement.

According to a survey of more than 2,300 hiring managers conducted for CareerBuilder by Harris Poll between Feb. 6 and March 19, 70 percent of employers use social media to screen candidates before hiring, up significantly from 60 percent last year and 11 percent in 2006. Some 3 out of 10 actually have someone dedicated to the task.

Employers aren’t just looking at social media — 69 percent are using online search engines such as Google, Yahoo and Bing to research candidates as well, compared to 59 percent last year.

“Most workers have some sort of online presence today and more than half of employers won’t hire those without one,” says Rosemary Haefner, chief human resources officer at CareerBuilder.

“Our survey found information technology employers are the most likely to check out a candidate’s social sites (84 percent), followed by leisure and hospitality (76 percent), financial services (74 percent) and professional and business services (70 percent),” she says.

This scrutiny on the part of employers can result in rejection for job applicants, with 54 percent of hiring managers reporting that social media content has caused them to reject candidates.

The top reasons for these rejections include postings of provocative or inappropriate photographs or videos, racist rants, information about drinking and/or drug use and complaints about previous employers.

In addition, posting too frequently and posts exhibiting poor communication skills are also “red flags,” Haefner says.

“I would say that most people have something on their current social media presence that can be construed or misconstrued as being inappropriate,” she adds.

On the other hand, “having no online persona can hurt your job search,” she warns. “Our survey found that 57 percent of employers are less likely to call someone in for an interview if they can’t find a job candidate online.”

“It really is important to have a social media presence, but our recommendation is that you manage it,“ says Christina Giglio, regional recruitment manager for Robert Half Technology & The Creative Group.

Giglio, whose domain is headhunting for tech and creative jobs, says job seekers should “type their first and last names into a search engine like Google and if they find any unflattering information or compromising images, untag yourself. Also pay attention to privacy settings.”

Of course, unflattering information has a way of persisting online and, this may become an issue, assuming you even get the job interview. “The thing that we always suggest is to be honest,” she says. “Most employers will be understanding.”

“It’s important that you use social media to highlight the best part of you,” Giglio says. “But employers don’t need to know everything.”