Why does file ownership matter within an RPM or DEB package?

### Context: I'm trying to convert a .deb package to .rpm using [alien](http://manpages.ubuntu.com/manpages/gutsy/man1/alien.1p.html) , I use this command: $ alien -r foo.deb but it complains thusly: > Warning: alien is not running as root! > Warning: Ownerships of files in the generated packages will probably be wrong. I think all alien needs root for is to guarantee that it has permission to create foo.deb's root-owned files for the foo.rpm output, but I'm not sure. ### Questions: 1. Do packages always need some root-owned files? 2. Why do they need root-owned files at all? 3. If I'm wrong, why does alien need root?