I've been reading up and copyright varies. basically it comes down to what is in their disclaimer on the cd/covers. Read below taken from copyright service uk:
COPYING, DUPLICATION, REPRODUCTION:
The right to produce a copy of the work.
Do you wish certain groups to be able to copy your work? if so what terms would you attach?
SELLING & HIRING:
Normally this would be expressly forbidden without the copyright holders consent.
DISTRIBUTION:
You may for example have written a shareware program which you will allow to be duplicated and distributed freely so long as you are identified as the author.
COMMERCIAL, PERSONAL, EDUCATIONAL:
Will you allow your work to be used differently by certain groups or individuals?
For example, perhaps you want to allow copying for private use but not for commercial gain.
LICENCES:
For software, commercial and educational documents in particular, the copyright disclaimer may carry information about obtaining a licence to reproduce the work.
By not obtaining a licence, use of the work may be considered in breach of copyright.
RIGHT TO BE IDENTIFIED AS THE AUTHOR.
If for example, the work is distributed without your control, you will wish to ensure that you are still identified as the author/copyright owner.
Hope this helps some . . .