Problem banned user - need to "soft" delete their contributions
 

I have been searching but must ask this directly:

I have a user who has been banned and has changed the images of links he posted in the forums so that they deface my boards.

I need to keep his posts for legal reasons but don't want them to display within the public domain.

What is the best strategy to keep everything he has written in a sense that can be reviewed? I would like, for example, to be able to "soft" delete his posts so that they are able to be reviewed by administrators on demand but do not appear in the forums otherwise.

Can you make any suggestions?

I have considered the options of pruning and moving posts/threads by username as well as renaming the user and so on...

Will