( CNN ) One of the most pernicious phrases in the debate over how to counter extremist use of social media is `` whack-a-mole . '' In national security circles , many believe that suspending social media accounts used by violent extremists is a pointless endeavor . They argue that , as in the children 's arcade game `` Whac-a-Mole , '' suspending accounts is a fruitless endeavor because , they claim , new accounts are created for every account that is suspended . To examine this assumption , technologist Jonathon Morgan and I collected data on millions of Twitter accounts , including tens of thousands used by ISIS supporters , and found substantial evidence to the contrary . In September 2014 , Twitter began to crack down on ISIS supporters who used its platform , suspending tens of thousands of accounts over the course of several months . While many users did create new accounts during the first month of the crackdown , the number of new accounts plunged after September , even though suspensions increased . Twitter has indicated that its suspensions fell at least at the high end of our estimated figure , possibly even higher still . The result is that suspensions are outpacing the number of new accounts successfully created , possibly by a wide margin . The size of ISIS 's support network on Twitter is shrinking as a result . Additionally , we found that the suspensions targeted some of the most active and effective users in the network , the professional activists who empowered ISIS to broadcast its propaganda to unsuspecting audiences by spamming hashtags such as # WorldCup and # CakeBoss . Not only has ISIS suffered a blow to its ability to spam others , its supporters on Twitter are so weakened that they are now hoist by their own petard . The hashtag that ISIS uses to promote its own messages has been taken over by opposing spammers , trolls and activists , who frequently tweet five times as much anti-ISIS content as ISIS can muster on any given day . ISIS content continues to be available online , of course . The number of suspensions is not sufficient to completely deny them the use of Twitter . But their audience is shrinking and their ability to game Twitter with manipulative tactics such as auto-tweeting `` bots '' has been significantly diminished . An estimated 10 % of tweets sent by ISIS supporters are directed at rebuilding their social networks rather than disseminating propaganda , and that does n't account for the additional impact of time lost to the process of creating new accounts and waiting for followers to find them . These are worthy goals , and they detract from ISIS 's ability to accomplish its online strategy of intimidation , provocation and recruitment , which is discussed at more length in my new book with Jessica Stern , ISIS : The State of Terror . ISIS users call the suspensions `` devastating '' and their fury provides evidence that suspensions hit them where it hurts . But that does n't mean suspensions are ineffective , any more than a cold day outside invalidates decades of temperature trends that show the impact of climate change . The view outside your window , especially if you are an analyst or journalist following a couple hundred terrorist accounts , will not always accurately reflect an online climate where tens of thousands of accounts are in play . While our study was only a preliminary look at this issue , it examined a body of data that dwarfs any existing study on the subject . While future research will help clarify the impact of suspensions over time , it is not likely to ever fully settle the complaints of the whack-a-mole crowd , who are as persistent as their favorite metaphor . Nevertheless , it 's time to move the serious debate away from the question of whether suspensions are effective and toward more complex issues with a better grounding in the available data . There are complications that arise from the suspension process . One of the most notable we observed in our study was the question of how people in the network behave under pressure . Our analysis suggested that the social network of ISIS supporters on Twitter is becoming more insular , with users following each other more and becoming less and less exposed to outside influences . While it is harder to enter the network in the first place and to stay there as an active user , it is possible that this echo-chamber effect might lead new users to radicalize more swiftly and more intensely . Tampering with an online social network , through suspensions or other means , is a form of social engineering , and we need to better understand what that means for users . We would be better served by research into such new questions than by continuing a tired debate about whether suspensions are effective at degrading the size and online distribution networks of extremist groups . It 's time to take this debate to the next level , and let the whack-a-mole mole stay whacked .
Many argue that suspending social media accounts used by violent extremists is a pointless endeavor . Data shows size of ISIS 's support network on Twitter is shrinking as a result of crackdown .