Phishing is an identity theft technique. Mirror sites similar in appearance to well known ones are created, and users are then randomly bombarded with spam having the graphic style of the faked site.
The aim is to "hook" the real customers of the site being plagiarised. An unsolicited e-mail with the counterfeited site's graphic style invites the user to go to the fake site to update personal information using an equally fake questionnaire.
The tricked user leaves telephone numbers, social security numbers, bank account details and sometimes credit card numbers. All of which is very lucrative information for the on-line scammers. See also brand spoofing and carding.