Protect Stored Messages

Hi fellows

My first time posting on this forum. I have a question, I hope is not in the wrong forum.

We are using JAJC as a client, and we can see our stored messages (history) with each user we talk to. But there is a special user, that everytime he can, he clears his messages history, so my question is:

Is there a Way to protect the history message not to be deleted?? or to protect private_store (in earlang)??

I don't know what is he hidding, but it's acting paranoic!! is there a way to store the chatting as in mail server you can store incoming and outgoing mails!!?

Thanks for your help!!

Sorry for my poor english, is there is something I didn't expain myself, please ask!!