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Ask Slashdot: How Much of Your Online Browsing Can Advertisers See?

Posted by BeauHD on from the expectations-vs-reality dept.

dryriver writes: We all know the phenomenon of browsing from an internet site A to a completely unrelated internet site B, and having identical ads follow you from site A to site B. Logic suggests that some kind of advertising system is following you from site A to B, and possibly onto subsequent sites C, D and E as well. Logic also suggests that this advertising system can now put together a nice long list of whatever you are looking at online. So here's the question: How much of your online browsing is "monitored" or "logged" this way by advertisers? Can there be any realistic expectation of privacy on the internet if the default behavior of advertisers is to track you as much as they can?

3 of 189 comments (clear)

  1. all by turkeydance · · Score: 5, Informative

    of it

  2. They use tracking IDs. by Static · · Score: 5, Informative

    Advertising content puts tracking cookies in your browser. Due to how cookies work, they are associated with the advertiser, not the website you're looking at. This means that the advertiser will see the *same* tracking ID whenever their content appears regardless of the site they're advertising on. Since they know what sites they're advertising on, they can match that with the tracking ID they've dropped on you to assemble a history of what sites you're browsing through. Including giving you the same ads.

    This is the "forgotten" reason why people run ad-blockers: to nix the tracking data across websites!

  3. Re:Don't care by Drakonblayde · · Score: 5, Interesting

    I used to use all that crap until I found out about PiHole. Now I just have my networks clients use it for the primary name server. The DNS requests to the ad servers never make it out of my network, so they never see any requests from me. For the few things that do make it through, uBlock Origin gets those until the PiHole lists get updated. It's also pretty damned effective at eliminating telemetry data from making it outside the network.

    Now, PiHole is basically just a glorified hosts file, but it allows me to handle things for the entire network instead of a device by device basis, as well as protecting those devices where I can't get at a hosts file (ie, mobiles)

    Of course, this doesn't do anything about websites that set cookies and share their own data with advertisers, but there are other tools for dealing with that.