". This is called mass domestic warrantless surveillance and it is illegal under any reasonable interpretation of the US constitution, and certainly shouldn't be allowed by private parties either."

I don't think this is correct. Google etc are private actors so no state action, no constitutional violation plus they get your legal consent whether you like the way they do it or not. Government agencies if they get the info must get a warrant or have exception or info's use is barred from court and can't be used against you. So why the claim it is illegal mass domestic surveillance? Hyperbole. Mass surveillance that IS used against citizens all the time is China in WeChat, mass camera use, etc. where there are no constitutional or other protections.