"The goverment must have power to spy on Whatsapp users' messages, Home Secretary Amber Rudd demands"
This should be re-written to this:
"The goverment must have power to spy on [all users 100% of the time] Home Secretary Amber Rudd demands"
...because that's really want they want isn't it?
That's exactly what they want and where it's all heading. Problem reaction solution the oldest trick in the book!