Suppose two git-annex symlinks (locked files) point to the same key.  If you unlock one symlink, and `annex.thin` is `true`, editing the file will change the contents pointed to by the second, supposedly locked, symlink.  

Maybe, with `annex.thin`, when one copy of a file is unlocked, all must be unlocked?

Also, with `annex.thin`, the [[invariant|internals]] that `.git/annex/objects/aa/bb/*/*` contains content with given key gets broken if the file is edited.  Might that affect other things, like metadata lookup? [[`git-annex-fsck`|git-annex-fsck]] reports this as an error.

[[`git-annex-drop`|git-annex-drop]] succeeds but does not actually drop the file.

Also, even if the current repo is trusted, with `annex.thin`, an unlocked file should not count as a trusted copy.
