Glenn E. Meyer Asked: "So how does Skynet or Hal know I'm a gun guy and then add such to my Times page? Tin foil hat?"
You're not going to like the answer and a tin foil hat won't help:
First off, I work in the communications and security business. Shame on everyone in the last 5 years that didn't stand up and scream about online privacy. The online privacy genie is, for practical purposes, out of the bottle and LONG gone. Second the information below (which is about 1/5 of what came up) was retrieved in 12 seconds, from a site that provides snipits of personal information that is typical of what is sold primiarly to advertisers, in the hope that customers want to buf the full package of info they have on hundreds of millions of people.
To answer your question directly, there are multiple services that provide location and web surfers' preferences to advertisers "to enhance *your customers* (that's you in this case) online experience", as one such service provider notes. They can track you jointly or severally by cookies, IP address, tracks, logins, various links to your email address(s), vendors you frequent and other methods. All of these little pieces put together a pretty good mosaic of an individual, often without a name, but more frequently, with the ability to provide more information about anyone in much more detail than your last 3 credit reports. All of this is perfectly legal as you generally give consent when you use a particular service, web page or vendor, who often sell or share the information. You gave your consent when you went to a particular website, but failed to fully read and understand their T's&C's. This is usually about 2/3 down the 20 pages in the Terms of Use or Service.
From there it's pretty straight forward to look at your on-line browsing history reference literally thousands of other databases and other online repositories to determine that for Glenn E. Meyer:
Are in your 60's
Are a Sagittarius
Like to travel
Own (with your wife A***) a $2-300K home in San Antonio located at XXXY F***** **** D****
Have an income of approximately $XXXXX
This was 5 lines of several pages available at no cost in about 12 seconds. The online ad guys can do this in about 1/100 of that time to "enhance your online experience". It's not rocket science any more.
These and many many other invasive data points are traded every day.
As for using the ad blockers, yes they typically work. The advertisers still know about you, but you're just not getting confirmation about it.
There are typically a lot more details available about most people. The sad part to me is how little people seem to care about the security of their information.
For practical purposes, there is no on-line privacy any more. Without legislation, it's only going to get worse, or more likely, will move offshore to a country that encourages the trading if not pilfering of personal information.
Good luck, be safe.
They can track your Google searches based on your IP address, and when you load the NYT site, the site sends your IP address to AdSense (or whatever Google's ad service is), which looks in the logs and says "hey this guy searches for guns alot, send him a gun advert". Now it might not be Google, it could be some other company, but Google is easiest to illustrate the point with.