The whole site. The site is in the best position to know what is publicly available and which is within the walled garden and should adjust their robots.txt or spider responses to match. You pee in the pool, you have to take a time out.
That line of thinking also begs the question whether only freely accessible information should come up on web searches, which would rule out any links to many professional journals which survive by subscription and/or fees per article. If you're punishing Wired for putting articles behind walled garden then it makes sense to punish all walled gardens and Google search becomes a search engine cataloging only free articles.
There is certainly a discussion to be had where major sites are allowing Google to spider paywalled posts such that the content comes up in results based on hidden-to-the-rube words, but that's for another time.