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A web admin creating a robots file helps search engines index the content better and therefore deliver more relevant results to the user, which causes the user to use that search engine more frequently, which leads to more ad revenue. Not tracking the user doesn't help the search engine because it limits the information about the user so ads cannot be sold.

It's completely self-serving on the part of Google (and others).
You're right. I forgot about that.
 
Great site!

According this site, Chrome offers better protection than Safari...

Safari:
Is your browser blocking tracking ads? ⚠ partial protection
Is your browser blocking invisible trackers? ⚠ partial protection
Does your blocker stop trackers that are included in the so-called “acceptable ads” whitelist? ✓ yes
Does your browser unblock 3rd parties that promise to honor Do Not Track? ✗ no
Does your browser protect from fingerprinting? ✗
your browser has a unique fingerprint

Chrome:

Test Result
Is your browser blocking tracking ads? ✓ yes
Is your browser blocking invisible trackers? ✓ yes
Does your blocker stop trackers that are included in the so-called “acceptable ads” whitelist? ✓ yes
Does your browser unblock 3rd parties that promise to honor Do Not Track? ✗ no
Does your browser protect from fingerprinting? ✗ your browser has a unique fingerprint
your browser has a unique fingerprint

This is what I'm getting from Safari:

Is your browser blocking tracking ads? ✓ yes
Is your browser blocking invisible trackers? ✓ yes
Does your blocker stop trackers that are included in the so-called “acceptable ads” whitelist? ✓ yes
Does your browser unblock 3rd parties that promise to honor Do Not Track? ✗ no
Does your browser protect from fingerprinting?

I think it all depends on how your network is configured and what plugins are used to block tracking.
 
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