That’s tinfoil hat nonsense. Of course there is privacy, otherwise those agencies wouldn’t be constantly lobbying for more invasive surveillance powers. What would be the point of that, if they could already read everything?
those agencies aren't the ones lobbying. take a look at the 'ngos' lobbying for chat control.
https://www.schneier.com/blog/archives/2015/09/how_gchq_trac...