tentacle: n.

A covert pseudo, sense 1. An artificial identity created in cyberspace for nefarious and deceptive purposes. The implication is that a single person may have multiple tentacles. This term was originally floated in some paranoid ravings on the cypherpunks list (see cypherpunk), and adopted in a spirit of irony by other, saner members. It has since shown up, used seriously, in the documentation for some remailer software, and is now (1994) widely recognized on the net. Compare astroturfing, sock puppet.