Oakland Mayor LIBBY SCHAAF is taking a tough stance against federal immigration officials, who are reportedly planning a massive Bay Area sweep of undocumented immigrants.A source tells the San Francisco Chronicle that immigration officials plan to fly in ICE agents from around the country...with plans to arrest more than 15-hundred people who are in the country illegally.KCBS Radio and Chronicle Insider Phil Matier was at a news conference where he asked Mayor Schaaf just how far she was willing to go.