Here's the biggest bullshit about this:
It wouldn't have stopped the attack if WhatsApp's messages weren't encrypted, or were vulnerable to being de-encrypted by an intercept.
Like firstly, an algorithm would have to be in place that, somehow, indicates 'based on the context of this message, we think the dude is planning an assault'. Or otherwise the police would have to already have made some decision to intercept this dude's messages, which I don't think they were with Masood. The only other possibility would be downloading all WhatsApp messages and decrypting all of them, before subjecting them to an algorithm that highlights potential terror plots.
So there's that first hurdle.
But then, the police would actually have to respond to it, after picking it out and actually going through it. Make the judgement on whether or not the message is actually serious, and then to see if they can somehow track its location or the intended target. In that sort of time - because no, I don't expect an immediate call down the line to officers surrounding Parliament - the attack has happened anyway and we're at where we are now.
Yes, there is an argument to be made around how we address the ability of the internet to facilitate crime and terror through anonymity. Trying to justify the simplest, most useless political approach through an impossible scenario - trying to learn Masood's potential contacts is one thing, implying the ability to do so would outright stop the attack is another - is not the way to do it.
