What is RMS’ solution to this problem?
I know what his solution is not. It's not a mechanism that conveniently enables the fine-grained surveillance of people that just so happens to be google's business model.
In Eve online you used to be able to have people (outside your contacts list) pay some cash in escrow to send you a message.
Uncompromisingly insist on only using things you have ultimate ownership and control over, even when that means dramatic and life-altering inconvenience, and where those things don't exist, build them yourself.
Unfortunately, "build it yourself" is relatively easy when it comes to software, and almost impossible when it comes to the hardware running that software. It doesn't matter if you have full ownership of a complete open-source stack if no hardware manufacturer will permit you to run unsigned arbitrary code. The lack of open hardware--chips that you could build in your garage using materials nobody could reasonably prevent you from acquiring--is the lynchpin upon which open source software will wither and die.