Shipud writes: In February this year, over 120 delegates of the DOMAINFest in Santa Monica, California came down with symptoms of a respiratory illness. The convention included a trip to the Playboy mansion, which later was identified as the outbreak source. The convention was held Feb 1-4, 2011. The first inquiry to the LA County Department of Health (LAC DPH) of a suspected Legionnaire's Disease outbreak was made February 11. But upon tracing the outbreak, LAC DPH officials discovered a trail of reports preceding February 11 in social media, including Facebook and Twitter. The Wikipedia entry for legionelliosis was updated almost at the same time as when the LAC DPH report was made. The researchers concluded that social media updates helped the track the outbreak both through going through delegates tweets and Facebook posts, and also in the fast dissemination of questionnaires to track the outbreak source.