Separate Reading list

I was wondering since we can only lock a folder with a comic that has been downloaded, is there another way I can prevent my son from reading some comics from my library? It's too easy for him to go to the import screen and change the libraries. I know I read some where its going to be too hard to have some kind of user structure. If it's also too hard to put lock on folders at the library level, has anybody else figured something out? If not, is there a way to run multiple copies of the YACReader Library on a single machine so I have have the different libraries out of different IP address'?
Thanks

I am afraid there is no easy solution for your use case. I will try to add better parenting control in the future.