LinkedIn is a popular professional-oriented social networking site that’s used by many IT pros, and it’s a great tool for those who are job hunting or just want to get acquainted with others in their fields of expertise. You have to be careful about how you use its many features, though. Recently a security research company discovered a way that CSS, used to allow users to customize the look feel of their posts, could be misused to perform attacks. LinkedIn responded an patched the flaw, but this points up the fact that even using a legit site can open you up to risk. .
Read more here:
http://www.securityweek.com/linkedin-patches-clickjacking-flaw-exploitable-css