Gender based on navigation history

Using the fact that browsers usually display and process visited and unvisited links in different ways, smart people have long thought of how to automatically track the visitor’s web navigation history.

First we display links to popular resources on the page (in a hidden frame, for example). Next, two options:

1) Write a script that runs through the links and determines their color through getComputedStyle, as described by Jeremiah Grossman . There is even a ready-made script for this .
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This method has a small drawback: JavaScript is required.

2) The same J. Grossman proposed an improved version using CSS . We define our own style in which the visited links will have a picture background: each has its own. In this case, the browser will do all the work for us. Then just look in the logs, which pictures were uploaded.

Why this may be useful (harmful): if a person has visited a certain URL, then, with a high probability, he has an account on the corresponding resource. This can be useful, for example, if you use a hole in the target resource.

Now, why I remembered about it, and why such a post title. One witty comrade with the help of the first technology decided to determine the gender of the visitor . His theory is that certain sites are visited by gender, so you can calculate the probability that you are of such and such sex. I, for example, 68% male.