Anonymous post

An anonymous post is an entry on a bulletin board system, Internet forum, or other discussion forums, without a screen name or more commonly by using a non-identifiable pseudonym. Some online forums do not allow such posts, requiring users to be registered either under their real name or utilizing a pseudonym. Sites such as Slashdot and Techdirt. Others like JuicyCampus, AutoAdmit, 2channel, and other Futaba-based imageboards (such as 4chan) thrive on anonymity. Users of 4chan, in particular, interact in an anonymous and ephemeral environment that facilitates rapid generation of new trends.

Online anonymity can be traced to Usenet newsgroups in the late 1990s where the notion of using invalid emails for posting to newsgroups was introduced. This was primarily used for discussion on newsgroups pertaining to certain sensitive topics. There was also the introduction of anonymous remailers which were capable of stripping away the sender’s address from mail packets before sending them to the receiver. Online services which facilitated anonymous posting sprang up around mid-1992, originating with the cypherpunk group.

The precursor to Internet forums like 2channel and 4chan were textboards like Ayashii World and Amezou World that provided the ability for anonymous posts in Japan. These “large-scale anonymous textboards” were inspired by the Usenet culture and were primarily focused on technology, unlike their descendents.

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Wikipedia