The teenage girls skipped school, grabbed their passports and hopped a flight out of the country in hopes of joining ISIS. The plan was discovered and the teens were sent back home to Colorado.

A 19-year-old American planned a trip to the Turkish border to marry an ISIS member she met online.

Another teenager living in Chicago was arrested before boarding a flight to Turkey to join ISIS fighters in Iraq.

These are just some of the stories when it comes to teenagers being lured by ISIS.

“They are basically using social media to do so,” said former FBI Agent Ken Williams.

In the past decade, ISIS has become incredibly media savvy, using the internet to push their propaganda videos and recruit new fighters.

“They (ISIS) have people that will see kids getting into their website and will start the recruitment process,"Williams said.

Experts believe ISIS has more than 2,000 people dedicated to online recruiting and much of that centers on teenagers in the Western Hemisphere, including the U.S.

They have more than 90,000 Twitter accounts and communicate with more than 20 percent of their followers in English.

“They are looking for people that are dissatisfied with their life,” said Williams.

In many ways, it’s like gangs recruiting young kids. ISIS offers a sense of purpose and preys on their vulnerabilities. The terrorist group uses highly produced videos to spread their propaganda in a way that is seductive to teenagers.

“It is very focused on young people," Williams said. "The videos appeal to that young demographic."

The longtime FBI agent Williams says catching these kids as they communicate with ISIS recruiters is almost impossible and the public plays a key role in catching them. He says there have been dozens of potential threats, thwarted thanks to people seeing or hearing something and then alerting authorities.

He also understands the FBI and other government agencies are in many ways outgunned from a sheer volume standpoint.