# Combating Web Tracking: Analyzing Web Tracking Technologies for User Privacy
## 3 Countermeasures against Web Tracking
### Tracking Prevention
#### 3.2.1 Mainly Used Tracking Prevention Solution  
To prevent tracking, many browsers and extensions block network requests directed to tracker URLs using filter lists. Brave enhances privacy by randomly generating return values for APIs commonly used for fingerprinting. Using the FPRandom method, trackers receive consistent fingerprinting results within the same session but receive varying values when attempting to fingerprint across different websites [54]. Chrome offers cross-site cookie blocking, but users need to install extensions like AdBlock, uBlock, or CanvasBlocker to block tracking, advertising, and fingerprinting. The mobile version of chrome is not as feature-rich as the desktop version. Specifically, advertising and fingerprinting blocking are not available on mobile versions, as well as the ability to install extensions. Edge uses Disconnect's blocking list to block trackers and advertisements. It blocks sites that perform known trackers, advertisements, and fingerprinting through the list. At this time, the user must use an extension program to block the fingerprinting API in addition to the known list. Users can build AdBlock Plus to block advertising on the mobile version [55]. Firefox also uses Disconnect's blocking list, similar to Edge, to block tracker, advertising, and fingerprinting. Mobile versions allow installation of additional advertising and tracking blockers, such as uBlock Origin, Ghostery, and Privacy Badger. Edge and Firefox block fingerprinting sites using Disconnect's block list, unlike Brave and Tor, which directly modify the browser's JavaScript API. Disconnect distinguishes fingerprinting from non-listed sites by the domain name. Safari uses Intelligent Tracking Prevention (ITP), which leverages machine learning to detect and prevent cross-site tracking by analyzing user interactions on the Internet. Safari also reveals domains that utilize DuckDuckGo's tracker radar list for tracking purposes. Furthermore, Safari not only blocks cookie-based tracking but also provides solutions to stop fingerprinting and simplifies system configuration, making it harder for trackers to identify user devices. Safari achieves this by avoiding the use of custom tracking headers and unique identifiers in Web requests [56]. Samsung Internet offers Smart Anti-Tracking, similar to Safari's ITP, using machine learning to identify and remove tracking cookies. Additionally, users can add ad-blocking lists such as AdBlock or Disconnect [57]. The Tor browser uses the Tor network to protect personal information and anonymity, which can randomly pass nodes running Tor routers around the world and arrive at their destination, preventing third parties from tracking Internet activity [58]. Brave also supports Tor network access, and although accessing the Web in this way enhances security, the Internet speed is very slow because it connects via multiple nodes, so there is a limit to using the Tor network for everyday purposes. In addition, as a way to prevent tracking,the Tor browser incorporates a NoScript extension to block unnecessary scripts [59]. However, developers do not recommend installing extensions, including advertising blockers (e.g., AdBlock), because installing extensions can make the browser's fingerprints unique. The developers have also designed it to give all users the same fingerprint in order to prevent fingerprinting. As a result, it will be difficult for trackers to extract a unique fingerprint for each user [60]. Finally, most advertising and tracking blockers compare users to filter lists for requested and responded resources and block advertising tracking content, allowing the browser to render them. To block content, extensions block requests to URLs written in filter lists or use CSS rules that hide elements to make ads invisible to users [61]. Meanwhile, Privacy Badger uses heuristic methods to block domains that collect unique identifiers after sending Do Not Track and Global Privacy Control signals to block third-party tracker, cookie, and canvas fingerprinting [62].