File Cabinet

Is there a way to restrict the file cabinet area to members only even if your groupsite is limited but public? (Like how the Members Profile area is restricted to only Members) This would really benefit us because we would like all our members to have access to a specific set of about 30 documents, but we don't want the general public to have access to them. The only other way I can see doing this is to copy each of those documents into each interest group folder... which complicates things for everyone. Maintenance would be almost impossible to keep up with. 

Thanks!