A user can make a copy or a replica of a 50GB database and you can not do much about it ,
We all know the annoying (and wonderful) feature that a user can mark thousands of documents and just copy them.
Then the user can paste them many different places, A local database, same original database (very annoying),..
You no longer have the essential control of the data.
There is a setting in the ACL presently to allow "Replica or copy documents" !
That sounds sweet ...and I am sure IBM meant well, but this one also prevents users from doing a copying of text from a document, which will prevent any user from doing their daily job.
This is my suggestion to fix this:
In the ACL on a database add these options instead, to set who are allowed to copy/replicate a database
and these to who are allowed to copy/paste documents
I would probably also consider splitting replica and copy permission into two separate entries
Maybe also creating an entry for copy text etc. is needed, I don't know if this will ever be use
See this blog entry for more background