US Patent 7876335 Methods and apparatus for redacting content in a document

A system redacts content in a multi-layered document by executing a content modifier process that redacts a first portion of content in a source layer and then automatically redacts related content in at least one target layer. The content modifier process overlays the source redaction region on corresponding areas of other layers in the document to identify target redaction regions in those other layers that contain target content. In turn, the content modifier process automatically identifies and redacts the target content within target redaction regions.