>>tech companies choose whether or not they'll store user data centrally
...until the USgov/NSA chooses for them. Also, while it's all great the Syncthing tool is open source I see that they have precompiled binaries. Now I ask you, what percentage of people will compile themselves instead of downloading the readily available binary? Especially Windows users? In short, syncthing isn't immune to the USgov/NSA. We're talking about the general public; not just hardcore techies who can download & compile source code. I can just get GPG & rsync if I wanted... but that's not the point. Me and the person I replied were talking about "services"(tech companies), not stand-alone tools.
Anyways, Syncthing doesn't even replace Dropbox. Syncing files is just one of Dropbox's several features. And without a 3rd-party central server, Syncthing won't be able to deal with the person who wants their work computer to sync with their home computer. That central server is how you get around corporate firewalls, NAT and port-forwarding. If there's another way to deal with this, I'd love to hear it.
Local binaries can be -- and are -- audited. The USgov can't simply push new code (and this is why web-style pushed upgrades are a bad thing).
> Me and the person I replied were talking about "services"(tech companies), not stand-alone tools.
Goalpost movement. Services that control both client and server, and all the data involved in it, CAN NOT solve this problem; this is why we have (and need more of) well-defined protocols with more than one client and server implementation thereof.
SaaS, with their plethora of proprietary protocols, are the antithesis of privacy rights and a vibrant open internet ecosystem.
Here's one for your list: http://syncthing.net/