What & Who discovers terrorist plots?

[davidbfpo]

Moderator adds: Copied from UK CT thread and edited down for this thread

The Independent:

Public tip-offs to terror police halve in year, officials warn as more UK plots foiled

Link:http://https://www.independent.co.uk...-a8741411.html

From the later:

Mr Basu said the flow of intelligence from members of the public was vital. “I know some people are still reluctant to speak to us,” he acknowledged. “To them I say, reporting your concerns to us won’t ruin lives, but it might save them.”
In 2017, more than 31,000 reports were made to counterterror police, but last year the number fell to 13,000.
In both years, more than a fifth of tips were “very significant”, leading to the identification of a suspect or plot, or aiding prosecutions.

Locally a senior CTU officer added a little, with my emphasis:

However, crucial intelligence from the public has helped the police and the security services have prevented 18 terror attacks in just under two years. Twenty-two per cent of all reports we receive from members of the public produce important intelligence which is helpful to our investigations. “Like other criminals, terrorists need to plan and that creates opportunities for police and the security services to discover and stop these attacks before they happen. So if you see or hear something unusual or suspicious trust your instincts and ACT by reporting it in confidence by phone or online. The important thing for people to remember is that no report is a waste of our time. Reporting your concerns to us won’t ruin lives, but it might save them."

Link:https://www.west-midlands.police.uk/...-west-midlands