Google/Facebook has been striving to integrate the public account with many important services. Google/Facebook are a monopoly/very dominant in email, social networks, navigation, smartphones, etc. Some online services already require a Google/Facebook account. Your social media account determines your credit score[1], or can get/deny you a job position. This is going to get more widespread.
A social media account has become mandatory, and the law should step in to protect our privacy and safety.
[1] http://online.wsj.com/news/articles/SB1000142405270230477310...