Google and dmoz lose expired domains fight

I often see domains which are in different dmoz and google categories
(children, news, disabled people, church, government ..) with porn content.

Seems to me like people register expired domains which are still
in dmoz and get high PR for their sites from both, Google and dmoz categories.

It also seems to me that dmoz and google are completely unable
to handle this situation. They aren't able to delete expired
domains from their database when they expire.

This is horrible. Google should not give so musch PR value
for dmoz as long as they can't handle this.