Best practices for data deletion on user account termination

Question

On a site that has a fair share of user-generated content such as forum threads, blog comments, submitted articles, private and public messaging, user profiles, etc; what is the

Answer 1

You should keep all the content and just mark user as deleted so other users won't be able to see his or her profile, username etc. Then another user should be able to register by the same name (since it should become free).