Section (g)(3) says that "Being responsible in whole or in part for the creation or development of information includes, but is not limited to, instances in which a person or entity... comments upon ... or affirmatively and substantively contributes to, modifies, or alters information provided by another person". This implies that one editor of a wiki could be held responsible for not noticing and removing illegal content posted by another user while they edit a page.

https://www.justice.gov/file/1319331/download