How to keep Facebook, Twitter from being terrorists’ hunting grounds

Democratic presidential nominee Hillary Clinton said that, if elected, she would try to curb terrorists from using the Internet as a recruiting tool.

"We will disrupt their efforts online to reach and radicalize young people in our country. It won't be easy or quick, but make no mistake – we will prevail," Clinton said in her acceptance speech at the Democratic National Convention.

But Clinton's statement raises questions over what can be done to prevent terrorists from using Facebook, Twitter and other social media as extremist hunting grounds.

"I believe [social networks] have been used by terrorist groups for years," said Elizabeth Boudine-Baron, an analyst with the Rand Corp., a nonprofit research organization. "I think Twitter and Facebook are major platforms being used. ... and YouTube. It can be hard to get rid of stuff, but we can make it harder for the casual observer to find so it's not the first thing popping up."

Online recruitment has been an ongoing issue in the fight against terrorism. "Twitter works as a way to sell books, as a way to promote movies, and it works as a way to crowdsource terrorism -- to sell murder," FBI director James B. Comey said in December, according to a report in the New York Times.

With the benefit of the Internet, and social media in particular, terrorists can expand their networks beyond their own borders, reaching into homes in the U.S., Europe and around the globe. The Islamic extremist group ISIS had a minimum of 46,000 Twitter accounts in the September-December quarter of 2014, according to a Brookings Institution study.

Now a teenager from small-town America can be spotted, recruited and tutored to launch an attack in his own community.