Be very careful what you post online. This is one thing I just can't say too many times. It is not only the teenagers that are getting themselves in trouble by posting on Facebook.  Javed and I have been teaching classes (on using the web for job hunting) and my part of the presentation is called How NOT to Hurt Yourself.

It's easy, if it is something that when read could cast the slightest "negative shadow" on you, don't post it! No matter how funny or witty you may think it is, don't post it.  You never know who may see it weeks; months or even years after you write it.

The following is an interesting article on the topic.

http://www.saleshq.com/careers/articles/2436-online-missteps-can-cost-you-a-job