From this Washington Post article

"Luc Portelance, assistant director of operations for CSIS, said the arrested men "are Canadian residents from a variety of backgrounds. For various reasons, they appear to become adherents of virulent ideology inspired by al-Qaeda." But McDonell later suggested investigators had found no direct connection with al-Qaeda."

So GUEST (and I checked that), al Qaeda is an Islamic extremist group. I discovered the supposed link because I read the articles C. Ham linked to.