The law is not a computer program. It sometimes relies on the ambiguity of human language, and uses human judges & juries to make reasonable decisions within that ambiguity.

I think, in your scenario, you would have a hard time convincing a jury that Google's access to your computer is unauthorized.

The same argument could be made about the security research in the article. I think the majority of potential juror would never find someone guilty or liable for this, but there is always the risk that you are unlucky and end up with 12 who would.

You have to post something on the pages served indicating "authorized access only" or similar.