The FBI stopped three Colorado girls  in Europe who were apparently on their way to join the Islamic State. What is most troubling about these girls being caught, is the idea that there are scores of teens who haven't been caught doing the same thing.

The identity of the three girls from Denver has not been revealed, but according to mashable.com, two of the girls, ages 15 and 16,  are sisters of ethnic Somali origin, while the third is said to be from Sudan. The girls are safe and back with their families, but the FBI is trying to determine exactly what their mission was.

What is disconcerting is the idea that these three girls in all likelihood represent a small fraction of disenchanted teens who may be looking to make a difference in the world. How many more have left the country to join forces with extremists in the middle east, only to return to the U.S. to wreak havoc on their homeland?

What were these girls thinking? What were their intentions?

How the FBI discovered what these girls were up to is both encouraging and disturbing at the same time.Exactly how much does big brother know about our daily transactions and intentions? But, yet, we are somehow grateful for its knowledge whenever a terrorist threat is foiled. Can we have it both ways - privacy and protection?