UPDATE FROM FLOATINGSHEEP.org: We have written and published a FAQ to respond to some of the questions and concerns raised in the comments here and elsewhere.
A map of hateful tweets sent in the continental U.S. between June 2012 and April 2013. Read the io9 article here.
For the full experience, check out The Geography of Hate interactive map. To read more about the research, visit Floating Sheep.