by identifying themselves by means of pseudonyms). In well-defined abuse cases, a designated authority may be able to revoke the pseudonyms and reveal the individuals' real identity. Use of pseudonyms is common among professional eSports players, despite the fact that many professional games are played on LAN. Pseudonymity has become an important phenomenon on the Internet and other computer networks. In computer networks, pseudonyms possess varying degrees of anonymity, ranging from highly linkable public pseudonyms (the link between the pseudonym and a human being is publicly known or easy to discover), potentially linkable non-public pseudonyms (the link is known to system operators but is not publicly disclosed), and unlinkable pseudonyms (the link is not known to system operators and cannot be determined). For example, true anonymous remailer enables Internet users to establish unlinkable pseudonyms; those that employ non-public pseudonyms (such as the now-defunct Penet remailer) are called pseudonymous remailers. The continuum of unlinkability can also be seen, in part, on Wikipedia. Some registered users make no attempt to disguise their real identities (for example, by placing their real name on their user page). The pseudonym of unregistered users is their IP address, which can, in many cases, easily be linked to them. Other registered users prefer to remain anonymous, and do not disclose identifying information. However, in certain cases, permits system administrators to consult the server logs to determine the IP address, and perhaps the true name, of a registered user. It is possible, in theory, to create an unlinkable Wikipedia pseudonym by using an Open proxy, a Web server that disguises the user's IP address. But most open proxy addresses are blocked indefinitely due to their frequent use by vandals. Additionally, Wikipedia's public record of a user's interest areas, writing style, and argumentative positions may still establish an identifiable pattern. System operators (sysops) at sites offering pseudonymity, such as Wikipedia, are not likely to build unlinkability into their systems, as this would render them unable to obtain information about abusive users quickly enough to stop vandalism and other undesirable behaviors. Law enforcement personnel, fearing an avalanche of illegal behavior, are equally unenthusiastic. Still, some users and privacy activists like the American Civil Liberties Union believe that Internet users deserve stronger pseudonymity so that they can protect themselves against identity theft, illegal government surveillance, stalking, and other unwelcome consequences of Internet use (including unintentional disclosures of their personal information and