Much like with sex though you may want to consider keeping yourself protected just on principle. There are way more malicous sites that you have to worry about. I highly recommend installing both Malwarebytes and Microsoft Security Essentials.
Microsoft Security Essentials: http://www.microsoft.com/downloads/d...2-33d813687a7f
You should always have atleast one anti-malware utility and a Virus scanner like the ones already mentioned or (Trend/McAfee).