How to remove your OpenStreetMap account
You should ask a sysadmin on the site. OSM is transparent about account removal (see link), however only automatic removal leads to a ‘white list’ label.
Direct removal link: http://wiki.openstreetmap.org/wiki/FAQ#How_can_I_close_my_account.3F
Helpful Trick: Removing online data
Helpful Trick: Remove third-party logins
If you signed up for OpenStreetMap using a third-party login such as Facebook or Twitter, you probably want to revoke all access from OpenStreetMap. Click here to find out how.