Gosh, not really. They completely control who can use the service, and any information they 'require' to register for the service.
> since walled gardens don’t have open specifications and documented APIs for third-party client implementations.
I'd like to point out that walled gardens will still openly invite folks to join, and give them tools that they could reproduce, but give them no way to experience the garden outside the walls.. including the tools previously given that are also useless outside the walls. That's exactly the case with keybase.
> About binaries: anyone who thinks source code is required for determining program behavior probably shouldn’t be auditing software in the first place. (Often having just the source code makes it more difficult, not less.)
Huh. I'm interested in hearing how having source code makes autiting more difficult, since that has not been my experience.