I might be wrong, but I believe this stopped working since "pointer files" are used in v7 smudge/clean filters and unlocked files:

$ git annex unused
unused . (checking for unused data...) (checking kingston/master...) (checking kingston/adjusted/master(unlocked)...) (checking master...) 
  Some annexed data is no longer used by any files:
    NUMBER  KEY

    [...]

(To see where data was previously used, try: git log --stat -S'KEY')

  To remove unwanted data: git-annex dropunused NUMBER

ok

Indeed, -S doesn't find anything here. I suspect that is because git's smudge/clean interface kicks in in --stat. The above text should add the --no-textconv argument to avoid that. At least it works here. :) -- anarcat

Nice catch, thanks! done --Joey