OAuth is a secure authorization protocol which is commonly used in conjunction with authentication to grant 3rd party applications a "session token" allowing them to make API calls to providers on the user's behalf.
Studies have shown that website registration forms are inefficient as many people provide false data, forget their login information for the site or simply decline to register in the first place.
A study conducted in 2011 by Janrain and Blue Research found that 77 percent of consumers favored social login as a means of authentication over more traditional online registration methods.
These logins are also a new frontier for fraud and account abuse as attackers use sophisticated means to hack these authentication mechanisms.
One such way that social media accounts are exploited is when users are enticed to download malicious browser extensions that request read and write permissions on all websites.
Because the researchers informed ID providers and the third party websites that relied on the service prior to public announcement of the discovery of the flaws, the vulnerabilities were corrected, and there have been no security breaches reported.