Two of my friends told me that my blog was broken. They tried it in their browsers, and the stylesheet files didn’t load.

It was interesting because I didn’t install any new WordPress plugin, or tracking tool.

My first reaction was to go and check the pixels (Mouseflow, Facebook, GA.) They were fine.

Then I realized it wasn’t a problem with the code. I was overestimating ad blockers and how stupid they are.

Building an ad blocker takes 15mins: browsers will expose an API to intercept incoming traffic (images, stylesheets, javascript files), and you can block anything you want via a browser’s plugin.

I assumed that an ad blocker would check cross-domain requests, analyze javascripts code, keep a record of advertisers’ domains. Not at all. They look for keywords like “ad” or “pixel” in the incoming traffic and block them.

The culprit was not a tracking pixel, it was a subdomain change: I renamed my blog’s URL to “” Ad blockers will block domain’s files that have the word “ad” in it.

Don’t think we are there yet in terms of privacy. Technology that should protect you from being tracked is dumb; dumber than the technology being used to track you.

The brains behind ad blockers are not the same as the ones building advertising platforms (nor they are being paid the same.)


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Leo Celis