When evidence emerged linking the San Bernardino shooting to ISIS, President Barack Obama called on Muslim leaders in the U.S. and around the world to speak out against the group’s violent ideology.
He urged Muslim leaders to not only speak out against acts of violence, "but also those interpretations of Islam that are incompatible with the values of religious tolerance, mutual respect and human dignity."
It’s a call that world leaders have repeated in the wake of increasingly frequent ISIS attacks — and one that Muslim leaders have already been heeding.
Ever since ISIS stormed onto the world stage last year, prompting a U.S.-led bombing campaign against the group in Iraq and Syria, Muslim scholars and community leaders have been on the front lines in the war against the group’s ideas, which are far from mainstream.
Shortly after ISIS leader Abu Bakr al-Baghdadi declared himself leader of the so-called "Islamic State," Muslim scholars published a 17-page open letter to Baghdadi, challenging everything from his claim to be "caliph," or leader of the world’s 1.6 billion Muslims, to the way his group "cherry-picks" verses from the Koran to justify its actions.
The September 2014 letter was translated into 10 languages and signed by more than 120 supporters, from the grand mufti of Egypt to a professor of Islamic studies at Massachusetts’ College of the Holy Cross.
In it, the authors argue that Islam forbids forced conversions, slavery, torture, the killing of innocents and the disfiguring of the dead — all of which ISIS has notoriously done and sought to justify in its own extensive, multi-lingual arguments.
Citing religious texts, the letter also says that Islam forbids the mistreatment "in any way" of Christians or "people of the book," and that it is "obligatory" to consider Yazidis — members of a religious minority that ISIS fighters have attacked and enslaved — as part of that group.
It ends by demanding al-Baghdadi desist from all of his actions, "cease harming others and return to the religion of mercy."
The letter racked up more than 120,000 likes on Facebook and signatures from notable scholars around the world, including the vice president and deans of Shariah law and theology from Egypt’s Al-Azhar University, one of the most renowned centers for Islamic scholarship in the world.
Since then, the chorus of condemnation has grown, yet ISIS has been notably successful at recruitment and savvy at steering its sympathizers away from mainstream and moderate messages.
ISIS propaganda demonizes and dismisses critics as "infidels," claims to be the one true voice of Islam and orders Muslims across the world to leave the "lands of disbelief" and move to its territory in Iraq and Syria.
Some efforts to disseminate challenges to ISIS’ religious authority come via social media, where they might wind up on the radar of potential recruits
In Indonesia, home to the world’s largest Muslim population, a 50 million-strong Islamic organization recently launched a global anti-extremism initiative that will disseminate counter-messages online.
A. Mustofa Bisri, the spiritual leader of the Nahdlatul Ulama or NU, recently told The New York Times that "the spread of a shallow understanding of Islam renders this situation critical, as … extremist groups justify their harsh and often savage behavior by claiming to act in accord with God’s commands, although they are grievously mistaken."
The Organisation of Islamic Cooperation (OIC), a 57-member inter-governmental organization that bills itself as "the collective voice of the Muslim world," is using a similar strategy to counter ISIS ideology.
The group recently launched a "messaging center" that will connect senior Islamic scholars with the sort of cutting edge social media strategies that has made ISIS such a powerful force online.
Amanul Haq, the head of the OIC’s Peace, Security and Mediation Unit, pointed out that the scholarly work against ISIS that already exists "simply hasn’t been communicated in ways likely to resonate with those who need to hear this message the most" and that the project aims to correct that.
Muslim community leaders in the UK are contributing to counter messaging as well, via an online magazine dedicated to "exposing the reality of ISIS."
On the ground, Muslim community leaders have taken to the streets repeatedly, from Berlin to New Jersey, to denounce violence in the name of Islam.
"We denounce [terrorist attacks] continuously," Abdul Mubarak-Rowe, the communications director of the New Jersey chapter of the Council on American-Islamic Relations told NBC Owned Television Stations in the wake of the Paris attacks. "It is not something that is found in Islam at all and we speak out vociferously against it.
Mubarak-Rowe also said that sweeping anti-Muslim rhetoric has become a problem in the wake of ISIS attacks.
"We are very disturbed by what we are hearing and what are seeing," he said
In his San Bernardino speech, President Obama urged Americans to steer clear of discrimination and bigotry and not let the fight against ISIS be "defined as a war between America and Islam."
"That, too, is what groups like ISIL want. ISIL does not speak for Islam. They are thugs and killers, part of a cult of death, and they account for a tiny fraction of more than a billion Muslims around the world — including millions of patriotic Muslim Americans who reject their hateful ideology," he said.
Though overwhelmingly dismissed, thousands have heeded ISIS' call.
According to the Soufan Group, a security consulting firm, about 30,000 people from 86 countries have traveled to Iraq and Syria to join ISIS. The firm points out that recruitment has more than doubled over the last 18 months.
Most recruits come from neighboring countries, with just 280 joining ISIS from North America and even fewer from the United States, where recruitment has been mostly reliant on social media.
Haq from the OIC acknowledged the challenge of trying to compete with ISIS’ notorious social media machine. But he added that that is why support for counter-messages is critical in the "battle for hearts and minds that's taking place across social media and in the wider world."