On Monday we had a 4.3 earthquake centered near San Jose. It was the strongest earthquake I recall in 15 years, probably because I was on the 5th floor of a concrete building that swayed for more than 10 seconds.
I quickly went to earthquake.usgs.gov to verify the magnitude. But what I hadn’t noticed is that they also have an automated system for gathering and displaying citizen responses. The system gathers location data (by zip or street address) and then walks through a structured questionnaire to classify local intensity from I (not felt) to X (very heavy damage).
This is a great example of user-generated content, in some ways better than Wikipedia. There are less motivations for bias (than, say, editing a post on abortion of George Bush). There are a larger number of reports, quickly, that tend to minimize the effect of error by any one contributor.
Most importantly, unlike Wikipedia, the aggregation of earthquake observations does not require any coordination or personal editing to aggregate the disparate contributions into a coherent whole.
Will we see self-reported epidemiology? Alas, between hypochondria and the litigation lottery mentality in this country, there is a much higher risk of self-serving bias for such reports than for earthquakes.