1. An apparatus for content filtering of data containers of multiple content types, said apparatus comprising: a plurality of content-specific filtering modules each implementing a set of content-specific rules for editing a component of a respective content type to produce an edited component; a root module configured to: apply preliminary rules for admission of a received container; and parse an admissible received container into constituent components and directing each said constituent component to a respective filtering module; and a multiplexer for combining edited components of said plurality of content-specific filtering modules.