You've heard it before: "The Internet is forever." So you should know that when your friend posts a picture of you staggeringly drunk on Facebook, it may come back to haunt you.

Businesses are now using social networking sites to scope out applicants, and that embarrassing picture — and other bad behavior found on your profile — may make your job search more difficult.

See also: 7 Tips for Keeping Your Day Job

In a recent Jobvite survey, over 40% of companies said they reconsidered candidates based on the content of their social profiles, including Facebook, Twitter and Google+.

Employers are more likely to view a candidate negatively if there are signs of illegal drug use or posts of a sexual nature on their profiles. Positive posts can influence decisions as well; over 60% of companies involved in the study said that evidence of volunteering or other charitable acts reflected well on the applicant.

Pictures aren't the only pieces of content that can change an employer's mind — text is also a major factor. Nearly two-thirds of participating companies said that profanity and spelling and grammar mistakes in statuses and tweets reflected poorly on job applicants.

What can you do to ensure your social media use doesn't ruin your chances for employment? The infographic below details types of online behavior that can help or hurt you in your job search.

Image: Flickr, Santiago Rodriguez