[magicalhippo]

I've come to hate hiding internals. Put them in a namespace which makes it clear there's no API stability guarantees, but make them available if needed.

As you note it's just pain with no gain to properly hide them. Users can't readily work around bugs or extend functionality.

[nirui]

Sometimes hiding internals is reasonable, but it could cause inconvenient. Exposing everything could make it harder to do interface management etc.

It's really a system design problem rather than access control: if you separate functional modules in a reasonable way, then it can be better reused.

[magicalhippo]

Only if you use a backwards language with non-existing namespaces. I don't see how it changes anything if you have namespaces. After all, private/protected/public are just namespaces, they are just implicit rather than explicit.