You slaved over your resume and cover letter, suffered through half a dozen interviews, talked money... and didn't get the job? Maybe it's because of a rude message you posted online and signed with your real name.

Online job search site CareerBuilder recently did a survey and study about whether hiring managers use search engines and publicly available data on the internet as a criteria in their hiring process. Turns out 26 percent did, and 12 percent used sites like MySpace in their screening process.

The scary news: 51 percent found enough online to justify not hiring a candidate (and a whopping 63 percent who used the social networking sites did). Here are their most common reasons for not hiring someone, based on what was discovered online.

• 31% - candidate lied about qualifications
• 25% - candidate had poor communication skills
• 24% - candidate was linked to criminal behavior
• 19% - candidate bad-mouthed their previous company or fellow employee
• 19% - candidate posted information about them drinking or using drugs
• 15% - candidate shared confidential information from previous employers
• 12% - candidate lied about an absence
• 11% - candidate posted provocative or inappropriate photographs
• 8% - candidate's screen name was unprofessional

Yow! Keep that in mind, ParisHiltonFootLover69!

However, some people actually found that people's web activities supported them getting the job. Here are the top reasons where the web helped people get hired:

• 64% - candidate's background information supported their professional qualifications for the job
• 40% - candidate was well-rounded, showed a wide range of interests
• 34% - candidate had great communication skills
• 31% - candidate's site conveyed a professional image
• 31% - got a good feel for the candidate's personality, could see a good fit within the company culture
• 23% - other people posted great references about the candidate
• 23% - candidate was creative
• 19% - candidate received awards and accolades

Interesting stuff, but mostly it's something to keep in mind next time you write a rant about your stupid boss on your blog, mention your arrest record in a web posting, or put up pictures of yourself in your sultry "naughty nurse" Halloween costume.

You can read more about the study here.