Teachers could not have been totally ignorant of the gang's values. The gang had a fascist website. They corresponded with fascists in other parts of the world. They made bombs in the garage. Parents should have known something was wrong.
Similar groups exist.
Far-right hate sites connecting with music from racist bands are organizing in Europe. Their creators can enter a Colorado home, or any other home worldwide, invited in from an Internet chat site or by an e-mail dialog with a stranger. But this Colorado event is not the Internet's fault. It is ours. It is likely this suburb's inability to talk openly about issues of racism and prevailing racist attitudes created fertile ground for the gang to grow.