When visiting some websites, I noticed that either captchas “I’m not a bot” began to appear, or the opening of the site was simply interrupted with a message about access to the site being denied without specifying a reason.

There are two ways to respond to this situation:

• try to “please” the site by giving it all the information about yourself that it asks you to pass on. For example, open in another browser - Chrome or Yandex with Cookies and JavaScript enabled and without using a VPN.
• convey a minimum of information about yourself, in the hope that the site will take a bypass path when there is no information about the visitor. This article is about the second method.

Information hygiene

There are sites on which advertisements or videos, including those created using AI, open dynamically (Dynamic HTML = JavaScript + DOM+CSS). Such videos can irritate the visitor by presenting negative images that are contrary to morality.

Often large sites host many scripts that intercept mouse movement and scrolling events for analytics or opening the same dynamic videos and advertisements.

Some information is “stolen” from the client: web browser, language, referring page (referer), date of previous visit and last session ID from Cookie, and a Cookie is added to the history to analyze user activity. When visiting again, an already changed set of information data (recommendation technologies) is issued.

All this unnecessary use and abuse of Web technologies to spy on users is not controlled in fact, which cannot but upset. But you can avoid this using information hygiene:

• do not visit sites that use such methods,
• do not tell the website a lot of information about yourself and your browser.

Types of user information leaks

1. Information collected server about the visitor. Collected by the server and does not require JavaScript enabled.
   referer: <?php print ($_SERVER['HTTP_REFERER']); ?>
client ip: <?php print ($_SERVER['REMOTE_ADDR']); ?>
user agent: <?php print ($_SERVER['HTTP_USER_AGENT']); ?>

or another option

<?php
foreach($_SERVER as $key => $value) {
echo '$_SERVER["'.$key.'"] = '.$value."
";
}
?>
Also, all requests to the server are written to the visit log. This legal method is used to analyze visits less and less, giving way to trackers - advanced counters for analyzing traffic.

2. Information collected by scripts on client- in a web browser. Requires images, JavaScript and Cookies to be enabled. There is complete “chaos” going on here to obtain maximum information about the user, where “all means are good.” For example, dozens of cookies are created (including cross-site cookies), invisible images - “beacons”, many analytical scripts and trackers (the source texts of which are often created dynamically, where <script></script> are sometimes added in real time, “on the fly”), encryption of scripts, use of the clipboard. At the same time, websites often only have a warning about the use of cookies, and the mention of analytics is hidden in the "Privacy Policy" document.

3. Information collected along the path of traffic - DNS requests are recorded by the provider, because they go to port 53/UDP in the clear.

4. Since the COVID-19 pandemic, offline information carriers in the form of QR codes have become widely used to navigate to websites. The QR code is printed on paper or film. Although most of them simply contain URLs, some of them are malicious (for example, they supposedly lead to a “house chat” in Telegram). This type of security threat is called an "air gap" because... information is not transmitted over the network.

Checklist

Before visiting sites that use powerful traffic research, I recommend the following checklist:

Short list of TL;DR

• Connect to your home VPN.
• Use LibreWolf or a browser with JavaScript disabled (appropriate add-on or in uBlock Origin - Settings - Default Behavior - Disable JavaScript)
  *Ctrl+Shift+Del- Clear browsing history (Cookies, temporary files)
• Set time zone according to web browser language.

How to disable default JavaScript in FireFox browser

Click on the uBlock origin symbol -> "Settings"

Disable JavaScript by default.

The crossed out </> icon is visible in uBlock origin - JavaScript is disabled.

You can enable JavaScript if needed and reload the page.

Result

The verification systems at the entrance to the site are at a loss.

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