Arnold Schwarzenegger, Leonardo di Caprio, Anne Hathaway, Arianna Huffington and Brazilian President Dilma Roussef are some of the Facebook users who chose to use the "rainbow filter" that was developed last week by two trainees in Mark Zuckerberg's group. The Facebook founder's profile also went rainbow. After 48 hours of intense work in the United States, the filter was made available to the general public in time for Gay Pride weekend and to celebrate the landmark ruling by the United States Supreme Court on the right to same-sex marriages. (AGI)