Is it me or?

[DoIKnowWhatImDoing]

These so called terrorists are always known to the MI5. Are they not supposed to gather intelligence on people that may be a threat to the country and stop these things from happening???
Or was this just another false flag event?

Unfortunately it's not a crime to have extreme beliefs - only to act on them.

What makes you think there have been any false flag events?

The police and security services do not have the resources to track everyone who might be a threat. Unless you want to live in a police state they never will. They therefore have to decide who to track closely and who gets less attention. They mostly get it right but inevitably they will sometimes get it wrong.

Like the IRA said after the Brighton bombing, the terrorists only need to get lucky once. The security services need to get lucky every time.