Here is Coursera's official response: http://blog.coursera.org/post/96686805237/response-to-reported-vulnerability-in-instructor-access http://blog.coursera.org

Here is Coursera's official response: http://blog.coursera.org/post/96686805237/response-to-reported-vulnerability-in-instructor-access http://blog.coursera.org/post/96686805237/response-to-report.... We have already implemented fixes and mitigation strategies for all of the vulnerabilities - including completely disabling type-ahead hinting for email address on our instructor interfaces (instructors must now enter the complete email address of a learner in order to manually enroll him or her in the instructor's course) and rate limiting and referrer header checking on APIs to slow down and stop enumeration attacks by third parties to discover learner enrollment status for courses. Finally, we would like to thank Dr. Mayer for reporting these security problems and helping us make Coursera a more secure and privacy conscious platform for our learners.