> How do you know the scale and how are you not sure that it's a vocal minority?

Read the articles and look for similar experiences for other banks. There's definitely a lot more noise about Monzo doing it. Maybe (as another comment suggested) there's a selection bias at work but I assure you it's a real thing, and appallingly handled by Monzo when it happens.

> Because maybe they are being forced to hide behind that?

That misinterprets what I said. If there are rules that say they don't have to be accountable for a misfiring fraud prevention system that hurts real people, where is the incentive to fix it?