Actually, you are explicitly allowed to decide what the site does, insofar as display is concerned. If it's client-side, you can do what you want. And blocking ads does get people somewhere - a less annoying internet.
As for your analogy...again, you're allowed to do that.
Actaully, the HTML of the "newspaper" directs my browser to connect to a bunch of other sites to download the sales flyers separately. I simply decline to fetch the ads. It's not like the website "puts ads in" and I "cut them out".
What's wrong with that? What laws is that breaking? I'm not even sure that's breaking any social contract.