The Council on American-Islamic Relations (CAIR) is a nonprofit 501(c)(3) , grassroots civil rights and advocacy group. CAIR is America’s largest Islamic civil liberties group, with regional offices nationwide. The national headquarters is located on Capitol Hill in Washington D.C. CAIR San Francisco Bay Area (CAIR-SFBA) is the organization's oldest regional chapter, based in Silicon Valley and serving the nine Bay Area counties' estimated 250,000 Muslims.