The House Republican Israel Caucus is calling on Twitter to ban the terrorist group Hamas from its platform.

On Tuesday, the sixteen-member caucus drafted a letter to Twitter CEO Jack Dorsey asking him “to ban designated Foreign Terrorist Organizations (FTOs) from Twitter and remove all content promoting terrorist activity, including banning senior Hamas officials and associates who use the platform to radicalize individuals to incite violence against Israelis.” Twitter’s policy on terrorism and violent extremism explicitly states, “You may not threaten or promote terrorism or violent extremism. ” Despite this, Hamas remains a Twitter user.

Hamas has been designated as a Foreign Terrorist Organization (FTO) since 1997, according to the U.S. Department of State. The letter sent by lawmakers cited several instances of Hamas’ most recent terroristic activities including the firing of nearly 700 rockets into Israel just last month. Further, one of those Hamas rockets killed American citizen Pinchas Menachem Prezuazman.

Now, Representatives Lee Zeldin (R, NY-1), Doug Lamborn (R, CO-5) and Joe Wilson (R, SC-2) are spearheading the fight to destroy Hamas’ public relations wing. The platform has allowed the Palestinian terrorist organization to incite and inspire violence against Israel and the Western free world. For example, The letter to Dorsey cites several instances of this including its use of the social media platform “to gather mass participation for its “Days of Rage” against Israel.”

Read the full letter below:

Dear Mr. Dorsey,

We write today to express our profound concerns regarding the use of your social media platform by designated Foreign Terrorist Organizations (FTOs). FTOs, including Hamas, use Twitter to advance their hateful ideology and propaganda. Last month, Hamas fired approximately 700 rockets into Israel killing innocent victims. It is imperative that Twitter, a United States Company, bans designated FTOs, removing all content promoting terrorist activity.

Congress has already determined that providing material support, resources, and intangible assistance to a FTO is a federal crime. Furthermore, the Supreme Court has upheld that federal law prohibiting individuals and groups from providing material support to FTOs does not violate the First Amendment.

Over the past several years, Twitter has made some progress by removing terrorist content from groups such ISIS and Hezbollah. However, more needs to be done to eradicate the spread of all terrorist activity by designated FTOs. Hamas follows a comprehensive charter that calls for the murder of every Jew and the destruction of the State of Israel through the covenant of Jihad. Hamas is well known for firing rockets and digging terror tunnels into Israel, murdering and kidnapping Israelis, and using women and children as human shields. Every year, Hamas uses Twitter to gather mass participation for its “Days of Rage” against Israel. Hamas, and other terrorist organizations use Twitter to recruit members, and praise “martyrs” that kill innocent Americans and Israelis. Hamas is recognized as a designated terrorist organization by not only the United States, but the European Union and Canada as well. That is why we also urge you to ban senior Hamas officials and associates from Twitter who radicalize individuals to incite violence against Israelis.

Twitter has a responsibility to stop the spread of terrorism on its site. We hope Twitter will take action without the need for additional Congressional oversight and legislative action.