Wikipedia:Not a new editor

Editors who have been banned or blocked may return to the collaborative project under the guise of being a new editor. If you run into such an editor add them to your watchlist and negate all dubious edits they make. When you have gathered evidence to substantiate your claims that they aren't a new user, but are an editor evading their block or ban in order to protect the integrity of the collaborative project the most common and effective approach is to file a report at WP:SPI, or you may email CheckUsers checkuser-en-wp@wikipedia.org with cogent evidence or, if there is private or off-wiki evidence, contact ArbCom at arbcom-en@wikimedia.org.