4. The apparatus of claim 1 , each document group comprising documents associated with a single container.
4. The apparatus of claim 1 , each document group comprising documents associated with a single container. 8. The apparatus of claim 4 , the candidate document feature block further comprising: a document classifier block configured to calculate a candidate document score corresponding to the candidate document; a container classifier block configured to calculate a candidate container score corresponding to a container to which the candidate document belongs; a domain classifier block configured to calculate a candidate domain score corresponding to a domain to which the candidate document belongs; and a classifier aggregation block configured to aggregate the candidate document, candidate container, and candidate domain scores; the classifier block further comprising: an adult status classification block configured to process the aggregated scores and the hub distance score using a classification algorithm to derive an adult status of the candidate document.