An illustration of a hacker working at a laptop. Bill Hinton | Getty Images

Hajjaj Fahd al-Ajmi, a Kuwaiti national with alleged ties to Al-Qaeda, had unearthed a novel way to secure funds for terror activities. Very recently, the man designated a terror financier by the U.S. and the United Nations had a robust and active presence on Instagram, broadcasting calls to attract financing to his 1.7 million followers on Instagram. But his burgeoning social media efforts came tumbling down after the Facebook-owned company shuttered his account, 24 hours after CNBC inquired about it. Instagram confirmed that certain accounts on its platform appeared to have been maintained by or on behalf of Hajjaj Fahd al-Ajmi, and that it has a legal obligation to disable those accounts. Al-Ajmi's case is not an outlier: According to analysts, terrorists are turning to social media platforms to secure material support for their operations, in part because of the anonymity and extensive reach they offer. The revelations come at a particularly fraught moment for tech giants such as Facebook and Twitter, which are already under scrutiny for facilitating Russia-backed propaganda in the run up to the 2016 U.S. presidential election. That trend particularly applies to terrorist operations in conflict zones such as Syria, according Nolwenn Bourillon-Bervas, lead terrorism analyst at independent risk consultancy the Risk Advisory Group.

Donors may not know where their money goes

Terror financing on social media can take several forms, analysts said — and donors may not even know that they're giving their money to fund violence. For some extremists, the platforms allow for broadcasting explicit calls for financial support. The financiers then direct potential funders to virtual communication platforms such as Skype, according to Nicholas Ryder, professor of financial crime at the University of the West of England, Bristol.

Extremists also encourage donors to use encrypted mobile applications that safeguard against external surveillance, posing a considerable challenge to counter-terror financing efforts, according to Bourillon-Bervas. One such popular app, Telegram, "has been used to communicate regarding the exchange or transfer of funds … [and to] coordinate recruitment" related to the Islamic State's operations in Syria and Iraq, Bourillon-Bervas said. In those cases, funds reach the financiers via wire transfers or social media platforms, according to Ryder. At other times, however, donors may not realize that their funds are going to terror organizations: Extremists also conduct fundraising under fake charities that indicate donations will be used for humanitarian purposes, according to an October report by the Royal United Services Institute (RUSI), an independent defense and security think-tank. Those layers of anonymity create further obstacles for governments to monitor and combat the illicit financing - already an "extremely difficult" task as with other forms of financial crime, according to Ryder.

Dangers and opportunities

Despite those regulatory challenges, financiers' move online also presents valuable opportunities for governments to disrupt terrorists' activities, according to the RUSI report. One example illustrates that scenario: The Israel Defense Forces currently monitor the accounts of suspects and their networks to identify any signs of a possible attack, the RUSI report said.

Furthermore, fundraising through social media could help authorities identify the financiers - although many factors prevent them from effectively clamping down on those individuals. "Clearly if [terror financing] is done via open source platforms it potentially exposes the fundraiser, but if the fundraiser is in Syria and they are targeting donors in Indonesia, how do the Indonesian police access that fundraiser?" said Tom Keatinge, director of the Centre for Financial Crime and Security Studies at RUSI. "It's almost impossible."

More regulation for social media giants?

Social media companies and governments must do more to curb the problem, according to analysts. To be sure, the tech giants have in recent years actively implemented counter-terrorism measures. Facebook this year outlined steps it is taking to combat the propagation of extremist messages. The firm said its artificial intelligence system detected and removed 99 percent of IS and Al-Qaeda-related content on its platform before they were flagged by people.