That's wrong. It's just the desktop GUI Apps that are proprietary.
The normal docker-ce package in your distro is still open source
Licensing
The Docker Engine is licensed under the Apache License, Version 2.0. See LICENSE
for the full license text
Doesn't this mean they can get sued under the International Energy Charta and have to pay damages?
Will be funny when the US ignores this treaty and it will be gone for good