Following a basketball game in Spain last weekend in which Israel's Maccabi Tel Aviv team beat Spain's Real Madrid, Twitter became awash in anti-Semitic tweets.
The racist and violent content of the tweets prompted several Jewish groups in Spain to file a complaint on Tuesday asking the country's prosecutors to investigate the tweets and their authors, according to the Associated Press.
In all, the Jewish groups say about 18,000 anti-Semitic tweets were posted to the site. Many of the tweets used degrading hashtags and included statements that referred to Adolf Hitler and the Holocaust, according to Spanish newspaper El Pais.
While many of the tweets were anonymous, the Jewish groups say they have identified five people who allegedly posted racist tweets. In the complaint, the groups asked that these five people specifically be investigated, according to the Associated Press.
"I am a firm defender of freedom of expression, but there must be a limit," Jai Anguita, president of one of the Jewish groups Bet Shalom, told El Pais. "We could say that these comments come from the high spirits after a [sporting] defeat, that they are almost jokes... But history has shown us where these jokes can lead."
"There are comments that are genuinely too much," Anguita continued. "Some of them talk about sending Jews to a gas chamber. We cannot allow for this to snowball; we need to stop giving the impression that incitement to hatred is permitted."
It's unclear if Spanish prosecutors will carry out an investigation into the alleged authors of the anti-Semitic tweets.
This isn't the first time that Twitter has been used as a forum for anti-Semitism. In 2012, a slew of anti-Jewish French-language tweets, which sparked a to get the names of the alleged culprits. Ultimately, Twitter to the French authorities in 2013.
When contacted by CNET, a Twitter spokesperson pointed to the social network's removal guidelines regarding offending content. The spokesperson said the company has created several tools to help people block, report, and mute other users.
"We work very hard to protect the experiences of people on Twitter, but unfortunately there are a small number of people in this world who try to harm others, both offline and online," the spokesperson said in an email. "On Twitter we have rules that determine how people can behave, and abuse and threats of direct violence are against our rules. When users register on Twitter, they agree to respect our policy."
Updated May 21 at 8:02 p.m. PT with comment from Twitter spokesperson.