We all love Facebook, but-----Did you know there are 400 million active visitors to Facebook? And that some 30% of employers are using Facebook to screen potential employees?

Don't make these Facebook blunders -- it could cost you your job.

1. Inappropriate Pictures -- Prospective employers or clients don't want to see pictures of you partying. Seemingly innocent photos can hurt.

2. Complaining About Your Current Job -- While everyone complains about work sometimes, make sure you don't do it online.

3. Posting Conflicting Information to Your Resume -- Uh oh, it says "Harvard" on your resume and "unheard of college" on Facebook. Yeah, too bad you didn't put that Harvard graduate degree in your online profile.

4. Statuses You Wouldn't Want A Boss to See -- "Planning" to call in sick so you can hit the slopes? Sure, you can have fun with your status -- but be smart too.

5. Not Understanding Your Security Settings -- Figure. It. Out. If you are going to use Facebook professionally, and even if you aren't, go through your privacy options and limit who has access to what info.

6. Losing by Association -- Watch out who can tag, post, or share to your profile. Remove it as soon as you see it, and "de-friend" questionable repeat offenders as needed.

Remember, Facebook can help you get hired ... or FIRED.

The best advice is to lock down your personal profile so that only friends you approve can see anything on that profile. Then, create a second, public profile on Facebook purely for professional use. Employers are looking, so don't get caught giving them your little black book instead of your resume.