Men purported to be Egyptian Christians held captive by the Islamic State are marched by armed men along a beach said to be near Tripoli, in this still image from an undated video made available on social media on Feb. 15. (Social media via ReutersTV/Reuters)

Since the Islamic State took over large portions of Syria and Iraq last year, videos of their killings have become a distinctive propaganda tactic for the group. The group has released graphic footage of its enemies being killed in shootings, beheadings, hangings, immolations, drownings and more, with each new video seemingly designed to spread anger and fear throughout the world.

The Islamic State is truly unique in the extent to which it has utilized graphic footage of violence and death. Yet even for a group so comfortable with terror, there may be internal concerns about what message these extreme acts of violence send.

On Friday, a number of news outlets picked up reports that Abu Bakr al-Baghdadi, the proclaimed caliph of the Islamic State's so-called caliphate, had issued a decree banning the release of videos showing summary executions. According to the Middle East Eye, a source in the Islamic State was quoted in Arabic-language media as saying Baghdadi issued the decree "to be considerate of Muslims and children's feelings who may find these scenes grotesque."

Such a decree would certainly be a shift in tactics for the group. In recent months, the violence of Islamic State videos had, if anything, escalated. When the world finally learned to expect graphic beheading videos, the group released a video of a man being burned alive in a cage. And while the group has attempted to find religious justifications for the brutality of these acts, a video released last month that featured a number of men drowning in a cage was notable for a lack of justification at all.

Experts who follow the Islamic State's violence have questioned the authenticity of the reports, however. "Anyone have evidence?" Charlie Winter, a researcher at the counter-extremism Quilliam Foundation said on Twitter. "None whatsoever," responded Pieter Van Ostaeyen, a Belgian historian and blogger who follows the group closely. "If it sounds like BS usually is," added Aaron Zelin, a Richard Borow Fellow at the Washington Institute and founder of the Web site Jihadology.

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A lack of hard evidence doesn't necessarily mean the reports are bunk: The inner workings of the Islamic State are sometimes opaque even to those closely following it. "It certainly could be true," Winter explained to WorldViews in an e-mail. "IS’s propaganda strategy is constantly evolving." However, Winter added that the single, anonymous source at the center of the reports gave him plenty of reason to doubt it.

"Anything is possible, but some things are more likely than others," warned J.M. Berger, a nonresident fellow at the Brookings Institution. Hassan Hassan, an associated fellow at London's Chatham House, pointed out that a purported letter sent by Baghdadi recently had attempted to regulate or centralize the graphic footage, rather than ban it outright: an important distinction.

Even the most hardened extremists have balked about publicizing graphic violence in the past, although tactical concerns may trump moral ones. In 2005, al-Qaeda deputy Ayman al-Zawahiri sent Abu Musab al-Zarqawi a letter ordering him to stop releasing videotapes of hostage killings. Muslims "will never find [the images] palatable," Zawahiri explained to the leader of al-Qaeda in Iraq, a group that would eventually become the Islamic State.

It is certainly true that the Islamic State may well have alienated a lot of potential supporters with footage of its violence. Winter pointed to the killings of Alan Henning and Abdul-Rahman Kassig (previously known as Peter Kassig) as events that completely alienated a lot of Westerners who might otherwise have supported the group.

"I would not be surprised if the group bans publicity for these videos when it becomes less necessary in deterring its opponents, which is the aim," Hassan said. "These videos distract from any effective work the group does in its territories in the way it governs the populace."

For now, however, there is little sign that the Islamic State will stop releasing videos of killings. Berger notes that just on Friday, a video was released that appeared to show a young child beheading a captured Syrian soldier. While the video does cut away before the act itself, Berger noted this may well be out of practical issues. "Hand knife beheading takes a disturbingly long time even when it's being done by adults," he explained. "A kid may not have the strength and stamina to do the whole job."

Read more on WorldViews:

The Islamic State routinely shares gruesome images of those it kills. But governments do it, too.

Why did victims in Islamic State beheading videos look so calm? They didn’t know it was real.

British Muslims plead with Islamic State not to execute hostage Alan Henning