Ibrahim Al-Moutaz's mother wanted her son’s body back. He had spent months trying to warn his neighbors about the Islamic State group in Raqqa, his hometown, and its brutal ideology. The least he deserved was a proper burial.

The militants executed 20-year-old Al-Moutaz last April in Raqqa, after he was caught disseminating incriminating information online about the terrorist group, also known as ISIS, which took control of the historic city in August 2013.

Al-Moutaz was a founding member of Raqqa Is Being Slaughtered Silently, an anti-ISIS activist group that's become one of the leading voices out of war-torn Syria, where journalists have essentially stopped going because of the enormous risks involved. Only insider activists are left to tell the world about the conflict, but the emergence of brutal groups like ISIS has made their job nearly impossible. Activists who previously had to protect themselves only from the regime of Syrian President Bashar Assad now have to watch their back for ISIS, too.

With more than 36,000 followers on Facebook and more than 20,000 on Twitter, Raqqa Is Being Slaughtered Silently provides daily updates on ISIS' movement in Raqqa, U.S.-led coalition airstrikes, the horrors of civilian life under ISIS rule -- and it has even provided information on ISIS hostages, most of whom were kept and killed in Raqqa. Throughout most of Syria’s civil war, now in its fourth year, the group's members have worked in secret.

“We’ve been three years under the Assad regime covering our real identities, so we have experience. We use fake names. But this was the most bad day (sic) in all my life,” said one of the group’s members, who uses the pseudonym Abu Ibrahim al-Raqqawi, via Skype. “We were really scared that under torture Moutaz told them our real names. But he didn’t say anything. So they executed him.”

ISIS executed 20-year-old Al-Moutaz Ibrahim on April 19, 2014, in Raqqa. He was a member of the activist group Raqqa Is Being Slaughtered Silently. Raqqa Is Being Slaughtered Silently

His death marked the beginning of a new phase of activism in Syria. The men and women in the country now have to worry not just about the Syrian mukhabarat, or intelligence services, capturing, imprisoning and torturing them, but also about the Islamic State group's far more brutal repression. Under Assad’s regime it was common for activists to be arrested and imprisoned, but under ISIS rule the risk is guaranteed torture and execution, possibly of family members as well.

Long gone are the days when Syrian activists openly recounted the torture methods used by the Syrian military on protesters. Those who still operate in Syria now focus less on President Bashar Assad’s barrel bombs, which create havoc in civilian neighborhoods, and more on the atrocities committed by ISIS. But their numbers are dwindling. Those who feel compelled to speak out against atrocities happening in the country have been forced either underground or out of the country completely.

The dissolution isn't just because of ISIS atrocities.

Rami Jarrah, one of the leading Syrian activists, who used to operate under the pseudonym Alexander Page, was forced to flee Syria to Egypt in 2012. He operated within a network of activists in Damascus that was targeted by the government.

“The problem is that the government always infiltrated us,” Jarrah said. “We found out that many people were informants to the government. That’s how the groups evaporated.”

Jarrah said his group of activists consisted of 25 people. “Two of them are in prison. The rest are dead,” he said.

Hundreds of activists who used to operate within Syria are now living outside of the country, the majority in Turkey in cities near the border like Gazientep and Antakya. Jarrah said these cities are also rife with Syrians who were never part of the activism community and are now “trying to make a living off of something that breathes off the war.”

“They are taking advantage of the situation,” he said.

Those who stayed inside ISIS territory, and without whom the world would never know about many of the group's atrocities, have been forced by security concerns to change their strategy. Today, there are four activists outside Syria who maintain constant contact with the 12 members still inside Raqqa, responsible for recording the “crimes of ISIS.” Those inside never speak to the press and they do not operate social media pages.

Initially the group documented each of ISIS’ crimes with photos and videos, knowing that those who were not in Syria would want proof. However, since the death of Al-Moutaz, they will no longer take those risks. Sometimes, news comes in the form of a simple tweet or a Facebook post. The group has been the first to report on several stories from Raqqa, including the killing of 26-year-old Jordanian pilot Muath al-Kaseasbeh in January. All of their reports have proved to be true.

“We are not responsible anymore for taking photos and videos inside the city, because we lost one of us because of this,” Al-Raqqawi said. “We care about our members. We care about giving real information and saying the truth, not about taking photos and videos.”

For many other anti-ISIS activist groups in Syria, even operating as clandestinely as the group does in Raqqa is not an option. In ISIS’ second Syrian stronghold of Deir Ezzor, media activists and journalists who used to be members of citizen journalist collective Deir Ezzor Free Radio have had to shut down.

“They are still there, but one of them was arrested so they are very careful now,” said one of the group’s members, who now lives outside of Syria and goes by the name Abdul-Hamid. “We are showing them [ISIS] that we are not working.”

The group closed its Facebook page when ISIS made major gains in Deir Ezzor last fall and subsequently released a list of rules that journalists had to obey in Deir Ezzor. Journalists and media activists who wished to continue working in the governorate had to swear allegiance to ISIS caliph Abu Bakr al-Baghdadi, had to refer back to the ISIS media office before publishing any “reportage” from the governorate, and were allowed to maintain personal social media accounts as long as ISIS was given access to them, according to Syria Deeply.

“My friends have told me not to come back now,” Abdul-Hamid said. “The problem is ISIS is now arresting people randomly and I may be killed without knowing why.”