Here's a powerful outdoor campaign running in Brazil, where a civil rights group called Criola is finding racist tweets online, using geotagging data to determine the location of the offenders, and printing the tweets with faces blurred on billboards near their homes.

"If she bathed properly, she wouldn't get that grimy."

"A black girl named "Maju"? You can't complain about prejudice, GFY."

"GFY dirty nigga, I dunno u but I wash myself."