Last fall, I was a candidate for a law enforcement job. During the orientation meeting, the background investigator outright told us that, if we make it to the background interviews, do not be surprised if there's a laptop on the table - they're going to ask us to log into our Facebook account. He said either that or we would be contacted and asked to temporarily set our profiles to public for the investigator to review. He said they would be looking for any evidence of inappropriate behavior (smoking pot, etc) and to see what kind of people we have on our friends list. They told us, "If there's something you don't want us to see, delete it now. You've been given fair warning."
.....Kelly
