Yes, moderators, feel free to change the title. But note that I'm not asking about backlinks per se.

#1 Search engines find pages by following links.

#2 Your logs say where your visitors came from, even if the source page is completely un-linked, un-indexed, thoroughly invisible. So you now know it exists. (I'm talking of course about human visits from real places, not robotic fakery.)

Question: If you've got a program such as Google Analytics that gives a third party access to this same information, does the third party now know that the source page exists? That is, do they backtrack from B to A if all they "officially" know about is B?