Twitter's CEO Dick Costolo
Twitter's CEO Dick Costolo (Reuters)

France's main Jewish student union has sued Twitter to force it to reveal the identities of users who post anti-Semitic comments.

A hearing is set for 8 January at a Paris court, said attorney Stephane Lilti, who represents the Union of French Jewish Students (UEJF).

The group was also urging more robust use of French laws on illicit content.

Twitter agreed to cancel anti-Semitic messages posted under the hashtag #unbonjuif, which means a good Jew in French, following threats of legal action by UEJF.

Offensive comments flooded Twitter in a "competition of anti-Semitic jokes", French daily Le Monde wrote, and the hashtag became the third most popular among French Twitter users.

However, more anti-Semitic messages have flooded the microblogging site since #unbonjuif was removed, with a new hashtag meaning a dead Jew in French jumping to the top of trending tweets.

Twitter refused at the time to comment directly on the tweets and said that the company "does not mediate content".

"If we are alerted to content that may be in violation of our terms of service, we will investigate each report and respond according to the policies and procedures outlined in our support pages," a spokesperson said.

Twitter also said it would not hand over details of account holders unless ordered by a judge. 

However, in October Twitter applied its local censorship policy for the first time by blocking access to a neo-Nazi account to users in Germany.

With the messages posted on the far-right Besseres Hannover account, Twitter enacted its new policy on censorship, whereby accounts can be blocked in individual countries if the content violates local law. The policy was announced in January, and has never previously been enacted.