With the advent of social media like linkedin and facebook it is easier for companies to look at a
candidate's profile on the open market. I have heard numerous stories about candidates who have pictures on facebook and/or postings that might be considered off color. This information is available to everyone. You never know who might be looking at your postings. Not too long ago I saw a number of postings by an individual that I had recently placed and as a friend I alerted him to be more careful about his postings.
Another overlooked faux pas that people miss is their e-mail address. Keep it simple and clean and there can be no mistaking you for a malcontent.