Lots of people sent anti-Muslim tweets after the Paris attacks. Most of those people were American. - The Washington Post

After analyzing a representative sample of the tweets, the researchers conclude that pro- and anti-refugee messages are roughly equal. But while pro-refugee tweets came from all over the world and were generally apolitical, the anti-refugee messages frequently invoked religion, were sent on partisan hashtags like #tcot and #impeachobama — and originated, overwhelmingly, in America.