Of all the privacy-related stories that ran around this year, I think that Facebook may have taken the lion's share of headlines, even if they were not the cause of all the commotion.
A victim of their own success, Facebook has drawn a lot of fire from privacy advocates and users alike. But the real problem isn't the social media site, but the lack of privacy employers (among others) give us on these sites. The year has seen dozens of stories of employers firing people and refusing to hire people after forcing them to surrender their Facebook password, or log in to allow the company to look into their personal life.
Keep in mind, this is a violation of the Facebook Terms of Service, as well as a persons private life. But in the war against personal privacy, 2012 has to go down as a major loss for the average consumer.