Context: An independent test in 2009 uploaded multiple versions of the same song to YouTube, and concluded that while the system was "surprisingly resilient" in finding copyright violations in the audio tracks of videos, it was not infallible. The use of Content ID to remove material automatically has led to controversy in some cases, as the videos have not been checked by a human for fair use. If a YouTube user disagrees with a decision by Content ID, it is possible to fill in a form disputing the decision. YouTube has cited the effectiveness of Content ID as one of the reasons why the site's rules were modified in December 2010 to allow some users to upload videos of unlimited length.

Question: What was the ultimate view of Content ID's performance after a 2009 test?
Answer: surprisingly resilient

Question: As of 2010 what is the maximum length of a video a user can upload given the proper authority?
Answer: unlimited

Question: How does one dispute the ruling of Content ID?
Answer: fill in a form

Question: What happened to the sites rules in Dec. 2010?
Answer: were modified

Question: What did a 2010 independent test find?
Answer: Unanswerable

Question: What is one of the reasons YouTube's rules were modified in December 2009?
Answer: Unanswerable

Question: What company ran the 2009 test of Content ID?
Answer: Unanswerable