Editing World Wide Web (section)

== Privacy ==
{{Main|Internet privacy}}
Every time a client requests a web page, the server can identify the request's [[IP address]]. Web servers usually log IP addresses in a [[log file]]. Also, unless set not to do so, most web browsers record requested web pages in a viewable ''history'' feature, and usually [[Web cache|cache]] much of the content locally. Unless the server-browser communication uses HTTPS encryption, web requests and responses travel in plain text across the Internet and can be viewed, recorded, and cached by intermediate systems. Another way to hide [[personally identifiable information]] is by using a [[virtual private network]]. A VPN [[encryption|encrypts]] traffic between the client and VPN server, and masks the original IP address, lowering the chance of user identification.

When a web page asks for, and the user supplies, personally identifiable information—such as their real name, address, e-mail address, etc. web-based entities can associate current web traffic with that individual. If the website uses [[HTTP cookie]]s, username, and password authentication, or other tracking techniques, it can relate other web visits, before and after, to the identifiable information provided. In this way, a web-based organization can develop and build a profile of the individual people who use its site or sites. It may be able to build a record for an individual that includes information about their leisure activities, their shopping interests, their profession, and other aspects of their [[demographic profile]]. These profiles are of potential interest to marketers, advertisers, and others. Depending on the website's [[terms and conditions]] and the local laws that apply information from these profiles may be sold, shared, or passed to other organizations without the user being informed. For many ordinary people, this means little more than some unexpected emails in their inbox or some uncannily relevant advertising on a future web page. For others, it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome. Law enforcement, counterterrorism, and espionage agencies can also identify, target, and track individuals based on their interests or proclivities on the Web.

[[Social networking]] sites usually try to get users to use their real names, interests, and locations, rather than pseudonyms, as their executives believe that this makes the social networking experience more engaging for users. On the other hand, uploaded photographs or unguarded statements can be identified to an individual, who may regret this exposure. Employers, schools, parents, and other relatives may be influenced by aspects of social networking profiles, such as text posts or digital photos, that the posting individual did not intend for these audiences. [[Cyberbullying|Online bullies]] may make use of personal information to harass or [[cyberstalking|stalk]] users. Modern social networking websites allow fine-grained control of the privacy settings for each posting, but these can be complex and not easy to find or use, especially for beginners.<ref>{{cite journal|last=boyd|first=danah|author2=Hargittai, Eszter|title=Facebook privacy settings: Who cares?|journal=First Monday|date=July 2010|volume=15|issue=8|doi=10.5210/fm.v15i8.3086 |doi-access=free }}</ref> Photographs and videos posted onto websites have caused particular problems, as they can add a person's face to an online profile. With modern and potential [[Facial recognition system|facial recognition technology]], it may then be possible to relate that face with other, previously anonymous, images, events, and scenarios that have been imaged elsewhere. Due to image caching, mirroring, and copying, it is difficult to remove an image from the World Wide Web.