This is a good idea, if the passwords are the ones people change *from* (i.e. once you change your password, it gets into that list). This way nobody can use th

This is a good idea, if the passwords are the ones people change *from* (i.e. once you change your password, it gets into that list). This way nobody can use the password anymore (with the idea that it is a weak now, for any reason). This is selfish, though. If that database of passwords leaks, they are prime candidates to test on *other* sites.