Sixty-eight million geocoded entries (tweets and check-ins) from 3.2 million users were collected from the Twitter streaming API for the period from September 11, 2010 through January 28, 2011. The Twitter API provides a random sample of tweets; nongeocoded tweets or tweets originating from outside the United States were discarded. In addition, users with fewer than 6 records, or those who check in too frequently (more than once in 5 seconds) or travel too quickly (faster than 1800 km/hr) were removed to exclude automated bots or other location spam.