To play a legal thought experiment (i.e. to play into CopyrightParanoia), for wikis, this implies that anonymous contributions belong to the site proprietor lest they are signed at a later date. Unsigning a contribution and refactoring it, however, may not be sufficiently derivative to constitute a new anonymous work. Under FairUse rules, a citation to the original quotation may be necessary, so it might be unlikely that anonymous text on a wiki is a) legal, b) consequently appropriate under the AnonymousCopyright provisions of the CopyrightLaw. That is, if there is no primary copyright (the original derivation was illegal), there cannot be secondary copyright (it cannot be assigned to the publisher).