Would you call this individual a "terrorist"?
This agent does not like to get his hands dirty. He does not blow things up himself. Instead, he turns on Fox News every day and waits for news that a terrorist act has taken place. An airplane blows up, a bomb goes of at a concert, a nuclear warhead goes off in a major city.
Instantly, he sends out a message claiming responsibility. "My organization's leaders ordered this attack. His followers executed it. Furthermore, if you do not meet my organization's demands we will do more of the same."
His message includes some vague threats that - that failure to meet these demands will result in some future bomb going off.
He is using terror as a political weapon. This sounds like a terrorist.
Well, what is the difference between this person and the religious leader who turns on the news, hears a report of some natural disaster, then releases a statement saying, "My boss God did this and, unless you meet our demands, he will do more of the same?"
The difference might be intent. Terrorist above knows that he is lying. But would he be less of a terrorist if he believed he served a boss who was responsible for those attacks? Would he be less of a terrorist if he really did serve such a boss?
No. He can find no escape in that direction.
Now, what if the terrorist boss gives a message to a random person saying, "I am going to cause some horrible thing to happen. When it happens, you release this message."
Well, that messenger is not, himself, a terrorist.
That is, not until the messenger declares himself a free and willing servant of the man who gave him the message. An attitude of shock and horror that somebody would use such tactics and the most reluctant cooperation would free him of the accusation. Loyal admiration and eager obedience does not.
These are the conclusions that follow if such a leader actually exists and gave a message to our agent. Nothing changes for the follower if the leader is imaginary. At best, the eager messenger can get off with a plea of "Not guilty by reason of insanity." at worst, his eagerness to serve such a boss, whether real or imaginary, leaves him, "Guilty as charged."
Remember, I am talking here of the willing and eager servant - a messenger - of a boss who would use weapons of mass destruction (earthquakes, cyclones, tsunamis, plague, floods, drought) as a political tool.
Would you call that messenger a terrorist?