How to remove your Wikipedia account
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 https://en.wikipedia.org/wiki/Wikipedia:FAQ#How_do_I_change_my_username.2Fdelete_my_account.3F
Helpful Trick: Removing online data
Publicly visible text/images often aren’t properly removed even when you succeed in removing an account. Try editing or removing them manually before removing the account itself. If you’re unsure what happens to your tracks: this can be found mostly in the Terms of Service/Privacy Policy; otherwise you can always contact Wikipedia and ask personally. By the way, removal requests don’t necessarily mean your data will actually be removed (e.g. due to legal obligations).
Helpful Trick: Remove third-party logins
If you signed up for Wikipedia using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Wikipedia. Click here to find out how.