Hat tip to FP Blog for this excellent article on the Lone Wolves / Lone Wolf aspect to modern terrorism; admittedly I thought there was a thread on the loners, so I've placed it here as every example bar one is American:http://www.foreignpolicy.com/article...olves?page=0,0

The lone wolf we need to worry about is truly solitary and self-motivated: someone who doesn't talk to people about his plans and doesn't require meaningful assistance from informed accomplices. Anyone who fails to meet those conditions is a different kind of threat...
I do like these two passages, which I have juxtaposed:
They are essentially al Qaeda volunteers -- people who step forward and offer their services to a terrorist organization that can provide them with resources and support.
They were receiving advice, concrete assistance, and passive reinforcement from people they believed -- rightly or wrongly -- to be part of larger terrorist organizations.
And who:
were actually undercover law enforcement agents or informants..