Twitter, even more than many other social media tools, can feel disconnected from the real world. But a group of students and professors at research site Floating Sheep have built a comprehensive map of some of Twitter's most distasteful content: the racist, homophobic, or ableist slurs that can proliferate online. Called Geography of Hate, the interactive map charts ten relatively common slurs across the continental US, either by general category or individually. Looking at the whole country, you'll often see a mass of red or what the map's creators call a "blue smog of hate." Zooming in, however, patches appear over individual regions or cities; some may be predictable, while others are not.

The map builds on an earlier Floating Sheep project that showed where President Obama was referenced with racial slurs, but it's far more comprehensive and well-constructed. Unlike many other studies, for example, the tweets weren't collected and analyzed algorithmically — a method that could accidentally collect non-derogatory uses of these terms. Instead, the team first searched through a year's worth of geotagged tweets for words, then had a group of students at Humboldt State University look at each one. Only tweets they found explicitly negative went on the map: a derogatory use of the word "dyke" would be added, for example, but one reclaiming the term for a gay pride parade would not. In total, the map charts about 150,000 negative, slur-filled tweets.

Since the map looks at only geotagged tweets, it's not a pure representation of Twitter, but this is standard practice for such mapping. Hateful tweets are weighted by the total number of tweets in an area, so you'll see the proportional number of slurs, not just areas with the largest number of Twitter users. Floating Sheep has much more information about the methodology, as well as some interesting analysis of the results.