With 51 percent of social network users taking advantage of more than one site, there's bound to be some crossover from one to the other, especially if you have the sites linked. You may post something you find innocuous on Facebook, but then it's linked to your LinkedIn work profile and you've put your job at risk. If you link your various profiles together, be aware that what you post in one world is available to the others. In 2009, a case of an employee caught lying on Facebook hit the news. The employee asked off for a weekend shift because he was ill and then posted pictures on his Facebook profile of himself at a party that same weekend. The news got back to his employer easily enough and he was fired. So if you choose to link your profiles, it's no longer a "personal life" and "work life" scenario.