> Why hasn't any evidence of such client-side interception ever been surfaced?
In such scenario only the target of the wiretap would receive the modified client application. Both google and apple allow pushing updates to small subset of users. It's not unthinkable that they also have the (internal) ability to push a specific update to a specific user.
But I guess now you'll move the goalpost to ask "Why hasn't any Googler come forward and admitted it's happening?" That is a fair question, but I think most people would see this legal spying as no big deal and perhaps even a good thing.
In such scenario only the target of the wiretap would receive the modified client application. Both google and apple allow pushing updates to small subset of users. It's not unthinkable that they also have the (internal) ability to push a specific update to a specific user.
But I guess now you'll move the goalpost to ask "Why hasn't any Googler come forward and admitted it's happening?" That is a fair question, but I think most people would see this legal spying as no big deal and perhaps even a good thing.