Yes, to a point, the 'internet is free'. But you are sort of twisting the point a bit I think. Not only does it cost money to have a website in many cases, but to be close to 'free' in terms of what you can post the theoretical person you are referring to needs to run their own web server, and their own DNS server, and hopefully they don't expect to need a domain name...

Otherwise, it is not in fact free. Registrars can take your domain (look what is happening to eu domains owned by UK folx) and web hosts, are in part responsible for the content they host and can refuse to continue to do business with you.

Hell, even if you roll your own setup, the ISP you use can still choose not to do business with you, leaving your entire setup offline.