keystone does not remove user accounts on purge

[koolhead17]

I tried un-installing keystone package but got warning

"" dpkg: warning: while removing keystone, directory '/var/lib/keystone' not empty so not removed.""

I want everything to be removed when am doing --purge

$ sudo apt-get remove --purge python-keystone
[sudo] password for precise:
Sorry, try again.
[sudo] password for precise:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  python-iso8601 python-openid python-webob python-routes python-sqlalchemy libxslt1.1 python-sqlalchemy-ext
  python-lxml python-greenlet python-formencode libjs-underscore python-pam python-openssl python-scgi
  libjs-sphinxdoc ssl-cert python-eventlet python-tempita python-migrate python-setuptools
  python-pkg-resources python-pastescript dbconfig-common python-decorator python-passlib python-paste
  python-pastedeploy
Use 'apt-get autoremove' to remove them.
The following packages will be REMOVED:
  keystone* python-keystone*
0 upgraded, 0 newly installed, 2 to remove and 3 not upgraded.
After this operation, 914 kB disk space will be freed.
Do you want to continue [Y/n]? y
(Reading database ... 49783 files and directories currently installed.)
Removing keystone ...
keystone stop/waiting
Purging configuration files for keystone ...
dpkg: warning: while removing keystone, directory '/var/lib/keystone' not empty so not removed.
Removing python-keystone ...
Processing triggers for ureadahead ...
Processing triggers for man-db ...

[James Page (james-page)]

I think this is OK; dpkg is just saying 'I installed this directory but I can't remove it because it contains stuff I did not create'.

The policy around what 'purge' should do with 'data' rather than 'configuration' seems grey.

That said, this package completely fails to remove the accounts it creates which is a bug.