Earlier quoted context omitted.
> using an Ad Blocker and viewing content is theft. Here's a different POV. Using an ad blocker is not theft: it's a negotiation. When I click on a link to your site from a site like HN, I have not implicitly agreed to whatever terms you would like to impose on me. I can't even really know them ahead of time. Instead, I'm sending my User Agent to negotiate fetching some resources. If I decline to fetch your ads, you…
Really? What header does your browser send to my server informing me that you are blocking ads so that I know to deny you my content?
Response 2: a few sites are already popping up messages asking you to turn off your ad blocker, which is at least a partial existence proof.
Response 3: if you want to know whether I got your ads, use cookies or make the request url unique to me, and then check that your ad servers served the appropriate requests before allowing your content servers to serve me content.
But seriously, I shouldn't be required to solve all these problems for you as a user in order to not be called a thief. If you want a more explicit contract, then require a log in. If that adds too much friction, invent a better a better solution.
*Edited to remove the inflammatory suggestion to go out of business if you refuse to negotiate.