Why doesn't the command do-release-upgrade doesn't require sudo?

I was wondering why the command do-release-upgrade doesn't require sudo? I mean, it does significantly change your system, so I would have guessed it requires sudo.

This is from ubuntu self, but it isn't that helpful. I just want to know how this is secure for the integrity for my system, if every user can access this command.

Thanks in advance.

[EDIT]:

I used a new terminal window, thus no sudo that wasn't expired yet, and I used the command do-release-upgrade NOT sudo do-release-upgrade.
So even with unexpired sudo I should be unable to upgrade.

[EDIT 2]:

I just ran do-release-upgrade in my terminal and look what happened:

So you don't have to worry about this anymore. do-release-upgrade is a python script located in /usr/bin which can be accessed by every user, but this script needs, as you can see, root privileges when it starts to perform actions on the system.

Put simply, do-release-upgrade implies sudo in the script so you don't have to type sudo yourself.