One video shows more than 100 prisoners paraded across the desert in their underwear , then lying face down as militants unleash a hailstorm of bullets into their bodies . Other images show crucifixions and public executions in towns overrun by terrorists . And recent footage showing the beheading of a second American journalist proves that ISIS wants the world to know how brutal it can be . The insurgents are experts at using footage of their crimes as propaganda to terrify those who disagree with their radicalism and to threaten foreign leaders . The visuals are as much a part of ISIS ' terrorism as its bloody march across the Iraq and Syria . In the video of American Steven Sotloff 's decapitation , the executioner has a stern warning for the U.S. President : . `` I 'm back , Obama , and I 'm back because of your arrogant foreign policy towards the Islamic State , '' the man says in the video , released just days after fellow journalist James Foley was beheaded . `` Just as your missiles continue to strike our people , our knife will continue to strike the necks of your people . '' Even a 7-year-old child was photographed holding a severed head . The picture was reportedly taken in Raqqa , the ISIS stronghold in Syria , where the boy 's Australian father had taken his family to join the fight . More decapitations . Publicized beheadings had actually stopped in years past . A decade ago , al Qaeda -- the terror group that spawned ISIS -- made headlines with a series of decapitations , including those of Americans Nicholas Berg and Eugene `` Jack '' Armstrong . Top al Qaeda official Ayman al-Zawahiri criticized the gruesome antics , and the decapitations stopped . But al Qaeda has since disowned ISIS , and al-Zawahiri has not condemned Foley 's execution . That means the beheadings could continue . But it 's not just Western captives who fall victim . Last week , a Kurdish man was executed in front of a mosque in Mosul in a video called `` A message written in blood , '' notes Charlie Cooper , Middle East researcher at the Quilliam Foundation . But because that message `` was directed at the President of Iraqi Kurdistan , this particular piece of propaganda did not receive widespread coverage in the international media , '' Cooper wrote in a piece for CNN.com . `` They have shown their willingness to kill anyone in their path -- not just Americans , not just Westerners , but Iraqis of all faiths , of all sects , '' U.S. State Department spokeswoman Marie Harf said . `` They 've shown their complete barbarism in doing that . '' The media 's role . Cooper said the media has a responsibility to treat ISIS propaganda carefully . `` Every time a still or clip from an ISIS video is shown , the group gets what it wants : the oxygen of publicity , '' he wrote . `` Of course , it is necessary that people the world over are aware of the atrocities occurring at the hands of ISIS , but journalists must be careful not to do the jihadists ' job for them . '' The decision on whether to publicize parts of the recent beheading videos have even divided journalists . International broadcaster Al Jazeera said it had decided not to show any images of Sotloff from the video -- a more conservative position than other TV networks . `` We suggest all media do the same , '' Al Jazeera 's public relations account said via Twitter , using the hashtag # ISISmediaBlackout . And while the video has been blocked from various video sharing platforms , they have also reappeared as many times , Quilliam senior researcher Erin Marie Saltman wrote . She said that kind of trend `` once again emphasizes that the new frontline for counter-terrorist practitioners is online extremism . '' Glossy recruitment tools . Part of the problem is the radicals are extremely tech- and media savvy . `` We are way behind . They are far superior and advanced than we are when it comes to new media technologies , social media , when it comes to video production qualities , and in disseminating their propaganda over the Internet , '' said Maajid Nawaz , a former jihadi and author of `` Radical : My Journey out of Islamist Extremism . '' Some videos used by the terrorists rival the production quality of Hollywood films . One hourlong video shows a collection of bombings , executions , kidnappings and beheadings . As one roadside bomb blasts a vehicle into the sky , two men in the background of the video chuckle . The recruitment tactics can be both blatant and subtle . For about $ 10 , supporters can buy a shirt with ISIS ' logo and phrases such as , `` We are all ISIS '' and `` Fight for Freedom , Until the Last Drop of Blood . '' And it may be no accident that a militant with a British accent fronted the video of Foley 's death . That kind of tactic could inspire more foreign jihadists , a former ISIS fighter told CNN . `` It is possible that the goal was to project the image that a European , or a Western person , executed an American so that they can showcase their Western members and appeal to others outside Syria and make them feel that they belong to the same cause . '' MAPS : Where do jihadis come from ?
ISIS militants are getting increasingly tech- and media savvy . Some of their videos rival Hollywood features in production quality . Beheadings by ISIS have increased after al Qaeda disowned the group . `` Our knife will continue to strike the necks of your people , '' a militant warns Obama .