Due to the fact that you do not need to provide any personal information, and Wikipedia needs to track who made what changes, the site is not on the black list.
Nevertheless, if you still fear your privacy: you cannot delete your account – only change your login. See http://en.wikipedia.org/wiki/Wikipedia:FAQ#How_do_I_change_my_username.2Fdelete_my_account.3F
URLS:
http://www.wikipedia.org
Please note that AccountKiller.com is not associated with the business listed on this page. AccountKiller provides easy-to-understand instructions and guides on how to cancel charges and relationships from the list of businesses on our site, we have no affiliation with these businesses.