Psychological warfare.
Let's say you're a mullah, and you have a number of members in your congregation who are not committed enough to do actual sabotage. So you send them off to go to various locations and act suspicious. They get arrested and let go. If you're lucky, they get hassled enough in the process to radicalize them. Meanwhile, you wear out law enforcement with false alarms so that when the real thing comes, they'll be slower to respond