Terrorism is defined by The Encyclopædia Britannica as the systematic use of violence to create a general climate of fear in a population and thereby to bring about a particular political objective.
When I went to London, I was shocked by the following "advertising" in a free newspaper:
Do you know someone who travels but is vague about where they are going? Have you seen anyone taking pictures of security arrangements? Have you seen someone with large quantities of mobiles? Do you know someone who visits terrorist-related websites?
I think that such advertising is intended at creating a general climate of fear. It is far more efficient than killing 2 or 3 people with a small bomb to spread fear, and you won't be arrested for publishing that !
I wonder who are the real terrorists...