I don't think it needs to be all server operators; It is not difficult for me to believe a Judge could find it "unlikely" that a 2013 email was forged containi

I don't think it needs to be all server operators; It is not difficult for me to believe a Judge could find it "unlikely" that a 2013 email was forged containing a valid Google signature, and I would not want to rely on you being on my jury. If Google were to publish their private keys, I could produce a forgery of my own in my defence. Of course it would be great if people were smarter than they are, but they're not, and I wrote some perl today, so it is hard to tilt at this particular windmill.