By Eric Beach & Adam Marcus
Among Internet users, there are a variety of concerns about privacy, security and the ability to access content. Some of these concerns are quite serious, while others may be more debatable. Regardless, the goal of this ongoing series is to detail the tools available to users to implement their own subjective preferences. Anonymizers (such as Tor) allow privacy-sensitive users to protect themselves from the following potential privacy intrusions:
- Advertisers Profiling Users. Many online advertising networks build profiles of likely interests associated with a unique cookie ID and/or IP address. Whether this assembling of a “digital dossier” causes any harm to the user is debatable, but users concerned about such profiles can use an anonymizer to make it difficult to build such profiles, particularly by changing their IP address regularly.
- Compilation and Disclosure of Search Histories. Some privacy advocates such as EFF and CDT have expressed legitimate concern at the trend of governments subpoenaing records of the Internet activity of citizens. By causing thousands of users’ activity to be pooled together under a single IP address, anonymizers make it difficult for search engines and other websites–and, therefore, governments–to distinguish the web activities of individual users.
- Government Censorship. Some governments prevent their citizens from accessing certain websites by blocking requests to specific IP addresses. But an anonymizer located outside the censoring country can serve as an intermediary, enabling the end-user to circumvent censorship and access the restricted content.
- Reverse IP Hacking. Some Internet users may fear that the disclosure of their IP address to a website could increase their risk of being hacked. They can use an anonymizer as an intermediary between themselves and the website, thus preventing disclosure of their IP address to the website.
- Traffic Filtering. Some ISPs and access points allocate their Internet bandwidth depending on which websites users are accessing. For example, bandwidth for information from educational websites may be prioritized over Voice-over-IP bandwidth. Under certain circumstances, an anonymizer can obscure the final destination of the end-user’s request, thereby preventing network operators or other intermediaries from shaping traffic in this manner. (Note, though, that to prevent deep packet inspection, an anonymizer must also encrypt data).