5.0 Earthquake or Computer Error?

According to the USGS, a 5.0 earthquake struck the Napa area at 12:43 p.m. But numerous Twitter users in the area are saying they didn't feel anything. "Apparently we just had a 5.0 earthquake. I didn't feel a thing," said fogcitywriter. In fact, other than news agencies reporting it, Twitter is eerily silent on any ground shaking. Oh, mysteries... Update: And the USGS is quick to say it was a false report. Let's hope it's not a harbinger! In any case, a good reminder to get prepared.