Racism evident behind some US social media
27 November 2012 Last updated at 03:59 GMT
In the decades since the civil rights movement helped end segregation in the US, openly racist language has largely disappeared from public discourse.
Yet the re-election of America's first black president on November 6 sparked an ugly outburst by some students at the University of Mississippi in Oxford.
Racial slurs initially made in posts on Twitter and Facebook were soon repeated at an impromptu anti-Obama protest where campaign posters were also burned. Meanwhile rumours of a riot on campus spread on social media.
Researchers say the incident has highlighted how some people are more prepared to voice racist views online than in person. And how social media can be used to mobilise people who share those views very quickly.
Social media was also used to bring together hundreds of students for a candlelit vigil the following night. The university authorities said the behaviour of a small minority had shamed the reputation of Ole Miss.
The BBC's Matt Danzico reports.