In times of relative political stability, governments routinely filter out international news outlets, information on reproductive health, religion, human rights and other topics deemed unfit. Women blogging about things considered mundane elsewhere, like being forbidden to drive or shop alone, are harassed by authorities. On the one hand, technology has made it easier to crack down on dissent, but the right technology can influence policy in good ways. In Mauritania, the use of censorship circumvention software after 2005 became widespread enough to prompt the government to stop filtering, since it was becoming a waste of time.

Even people living in countries where free speech is protected by law need anonymity for political activities. People blogging about political views that differ from the prevailing attitudes in a small community may lose a job or face boycotts if they run a business. In a company town, writing about the misdeeds of the company that employs your neighbors may be dangerous. Telling people about corruption could lead to harassment from guilty officials.

When someone finds the courage to leave an abusive relationship, the support of victims' advocates is vital. The Internet can help a survivor find counseling, shelter, and encouragement from people who have gone through the same process. Sadly, stalkers are also using technology to find their victims. Abusers monitor web browsers to see if a victim is planning to leave. Information about a shelter's location can be found in email headers, forcing abuse survivors to relocate. According to the U.S. Bureau of Justice Statistics, over one in four people who are stalked experience some sort of cyberstalking. Though some software in a stalker's toolkit is installed on a home computer, IP addresses can reveal which internet cafe or library someone uses to get online. Even if you don't have a stalker, hiding your IP address can be a good idea. Kids and adults alike are advised not to tell strangers where they live, but an IP address can reveal it for them.

Sting operations fail if criminals can tell that the police are connecting to message boards and chat from a government network. The information disappears. Insurgents may be looking for soldiers connecting to their defense department's computers back home. Anonymous tip lines are not so anonymous if someone telling authorities about crime is the only person in the neighborhood connecting to a government website. Without anonymity, going after organized crime can be dangerous to officers and their families.

Some companies do not reveal how much they know about their customers, or who sees the information. Some Internet Service Providers feel entitled to sell data collected from their subscribers to marketers. Though they claim that the information is not tied to any particular users, it is easy to find someone based on their search history. Information about visits to banking websites, searches for details on pre-existing health conditions, or other sensitive online activity could be damaging in the wrong hands; whether made available through carelessness or commercial interest.

Privacy online can protect people offline whether they are organizing protests, covering the news, blowing the whistle on threats to public health, or just blogging about daily life. In the "real world" assaults on privacy like peeking in windows, opening mail, or breaking and entering are obvious crimes. In the online world, however, assaults on privacy are subtle and unyielding. These threats to your health, your wealth and your well-being have no "opt-out" button. They have no "scrub my data" option. Your online activities, e-mails, bank transactions and everything else can be used to trace where you are and who you are. Using software like Tor gives ordinary citizens more choice about the information they reveal online.

For more information about online privacy and circumventing internet censorship, visit the Tor Project's website.

By The Tor Project

The XMMS2 Team Hard at Work