FILE - In this Jan. 11, 2014 photo, Serena Williams of the United States speaks during a news conference ahead of the Australian Open tennis championship in Melbourne, Australia. Beats by Dre, the headphone company held two events Friday, Jan. 31, 2014. Williams along with other celebrities Anthony Mackie, Jerry Stackhouse, and Jermaine Dupri attended a performance by British singer Estelle. (AP Photo/Aaron Favila)