http://www.slate.com/articles/news_and_politics/politics/2015/01/_jesuischarlie_the_default_mode_of_showing_solidarity_in_the_hashtag_age.html

It took less than an hour for the hashtag to appear. When gunmen attacked the Paris offices of satirical newspaper Charlie Hebdo on Wednesday morning, French onlookers mourned the murdered journalists by tweeting #JeSuisCharlie. Soon, Charlie Hebdo had updated its website with a guide to translating the call for supporters around the world—#YoSoyCharlie, #IchBinCharlie, #IAmCharlie. As the violence spread in Paris, the hashtag fractured into countless iterations: #JeSuisAhmed, in support of the Muslim police officer Ahmed Merabet, killed while patrolling the street outside the newspaper’s offices; #JeSuisJuif (“I am Jewish”), after hostages were taken inside a kosher grocery store; #JeSuisParisien extended solidarity to all the people of the city.