As already written, I would better use an authorization check, you could insert it in BAdI FI_AUTHORITY_ITEM, but as this BAdI only provides BSEG you may be required to loop at other items of the document in your code (check actual requirement)
This will provide check for FB03, but you may have to add the check in other "list" reports (e.g. ALV item lists).
Regards,
Raymond