The UK's Home Secretary Amber Rudd, fives days ago said "WhatsApp must be accessible to authorities", following the Westminster attack.

She summoned some big tech firms yesterday to tell them how unacceptable it is that the police can't read encrypted messages.

All this is going to do is invade the privacy of regular people, and force 'terrorists' to go off-the-grid which will make them even harder to track. The IRA were pretty good at terrorising without any kind of electronic communications - encrypted or not.

ISIS have already built their own chat application, allegedly, and distribute the APK privately. If the government ban e2e crypto in apps like WhatsApp/Signal/Telegram, expect to see more such apps from groups who politicians can't exactly summon into their offices for a chat.

https://techcrunch.com/2016/01/16/isis-app/

I'm completely against banning encryption, and also against the argument I'm about to use, but the devil's advocate to your comment is to claim that if the only people using encryption are the "bad guys", detecting encrypted data on the networks is enough to spot a "bad guy", even if you can't read their data.

Sure, that is a potential issue with the argument. But the broader argument is that you can't make crypto go away by wishing. You can't unpublish bcrypt, libsodium, OTR, Signal Protocol, and you certainly can't unpublish the maths they are based on.

All you are really doing is making it inconvenient for normal, law-abiding folk to use strong crypto. A suitably motivated attacker (think ISIS, al-Qaeda etc.) could adapt to a world without crypto using some kind of steganographic approach (three poop emojis and a Miley Cyrus gif = blow the building up!). Every approach you take could be manipulated by the bad guys to their own advantage.

Because the previous ways of communicating while working for a company with a compliance department that are hard to subpoena weren't on hundreds of millions of people's cell phones? Not saying that means the law should go after WhatsApp or it's WhatsApp's fault (I would strongly argue against both), but that doesn't mean it being made easier and deniability becoming more plausible isn't the cause.

What do you mean? How is WhatsApp more "plausibly deniable" than saying these things to someone in person?

Probably due to fewer evidentiary "crumbs" left behind. No witnesses to meetings, conversation eavesdroppers or recorded calls --now everything is more or less deniable and irrefutable, unless one of the parties decides to double cross the other.

You cannot prosecute someone based on hearsay. In someways Whats App makes it easier because you could take the phone as evidence and see a record of all non-deleted correspondence complete with time stamp rather than trying to build a case based on two buddies grabbing a beer together.

Which is why a lot of these technologies are targeted. Not because encryption makes it harder for enforcement agencies since there's always been a plethora of ways to communicate in secret. But because gaining back doors to these applications makes it easier for them than it's ever been.

Sadly the point enforcement agencies always overlook is they're basically just fighting a game of "wack a mole". Encryption isn't something that's going to go away. Not even if you legislate against it. People know it exists and there are a thousand different ways to run software on your handset - even just via web sites directly thus bypassing all the controls for side-loading native apps. So all this posturing about the "evils" of WhatsApp is just a monumental waste of everyone's time.

IIRC unencrypted chatroom logs were used in the investigation against banks rigging FX https://en.m.wikipedia.org/wiki/Forex_scandal