Here is Google's press release from the Huffington Post article: This year we started accepting doodles from kids even if their school hadn't registered for th

Here is Google's press release from the Huffington Post article: This year we started accepting doodles from kids even if their school hadn't registered for the contest. To help us keep entries distinct and remove duplicate entries from any particular student, we asked parents for limited information, including the last 4 digits of a student's social security number. We later updated our forms when we recognized that we could sufficiently separate legitimate contest entries while requesting less information. To be clear, these last 4 digits were not entered into our records and will be safely discarded. As for the city of birth: The city of birth helps us identify whether contestants are eligible for the contest, as winners must be either U.S. citizens or permanent legal residents of the U.S. The information isn't used for any other purpose." Source: http://www.huffingtonpost.com/bob-bowdon/why-has-google-been-colle_b_825754.html http://www.huffingtonpost.com/bob-bowdon/why-has-google-been...