Anonymous may refer to any of the following:
1. Anonymous is a term used to describe a person or computer that cannot be identified. For example, anonymous users may connect to an FTP server that allows it to send and receive files from that computer. Although many services do allow Internet anonymity, it's crucial to realize that there's no such thing as being 100% anonymous on the Internet.
2. Anonymous is the name of a hacktivist group that was established on 4chan in 2004. The group is often represented with the shown logo of a person in a suite with a question mark for a head. When in a gathering, Anons (Anonymous members) often wear Guy Fawkes masks to keep their anonymity.
The group is associated with DDoS and other attacks that have targeted corporate, government, and religious websites that it feels contributes to Internet censorship and injustice. Such targets include the Church of Scientology, the Motion Picture and Recording Associations, MasterCard, PayPal, Sony, Visa, and the Westboro Baptist Church.
The Anonymous group has been called "freedom fighters," "cyber terrorists," and was even named one of the "100 most influential people" in the world by Time Magazine in 2012. Since the group is anonymous, it has no leader and membership is open to anyone willing to state they're a member. The few rules that the group does have include not disclosing one's identity, not talking about the group, and never attacking the media.