https://launchpad.net/safe-rmThis package provides a tool intended to prevent the accidental deletion of important files by replacing rm with a wrapper, which checks the given arguments against a configurable blacklist of files and directories that should never be removed. Users who attempt to delete one of these protected files or directories will not be able to do so and will be shown a warning message instead. Protected paths can be set both at the site and user levels. (dpkg package description)
20KB's but provides an extra layer of protection against not only accidental deletions but social engineering as well, the error message could be a bit more clear about how important the directory is.