New York (CNN Business) Trolls on the online forum 4chan celebrated on New Year's Day as a fake Twitter (TWTR) account seeking to stoke tensions between Jewish and black Americans amid a string of anti-Semitic attacks in New York provoked outrage. Even as the trolls celebrated, the account went unchecked by Twitter for hours despite dozens of users saying they reported the account to the social media company.

The incident is more evidence of how trolls work to increase racial division in the US. It also raises questions about Twitter's commitment to combating hate on its platform and how quickly it will respond to fake accounts seeking to stoke such divisions during an election year.

"As a fellow Jew who was frightened by the string of anti-Semitic attacks, I am frightened," the fake account, which used the name "Elaine Goldschmidt," tweeted Wednesday. Using the n-word to describe black Americans, "Goldschmidt" added they "were supposed to be on our side. Now, we have lost control of them."

The account bore clear hallmarks of the kind of fake beloved by racist trolls: It used a supposedly stereotypical Jewish name, its bio contained extreme statements that trolls use to parody liberals, it was just set up on Wednesday, and its profile image was a stolen picture of a real person -- a Scottish comedian who's been a 4chan target and who did not authorize the use of her photo.

Still, the tweet picked up hundreds of likes and retweets. And Twitter users who reported the account Wednesday were told by the social media company that the account did not break its rules.

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