Also I would not consider the examples of tumblr and reddit to be relevant. A person's blog on myprofile.tumblr.org is still the tumblr organization. This would be true for reddit even if they didn't redirect. Reddit admins moderate content on all subreddits.
When I read > I have been taught and tell my users to check the domain to verify a website is real.
I was thinking more of control of the content as "ownership" of the domain.