Adding to databases: your thoughts are invited

I have just been asked an interesting question and, while I think I know the answer, the question is worth sharing. The object of the question is a database. At this stage it is not clear whether the database is protected by copyright or sui generis database right under the Database Directive (Directive 96/9): both are possibilities. The act to which the undisputed owner of the database objects is not however the unauthorised extraction or re-utilisation of the database but, curiously the unauthorised addition of fresh data.

The question is this: what sort of protection does the law provide for against such an act?