Copyright is automatic and does not require a visible license. Any provided licenses are just that, a license, they do not strengthen, remove nor water down copyright.
E.g. If you post something under a CC attribution license, and someone shares it without attribution then they are breaking copyright, not breaking the license. They aren't licensed.
On the other hand, if no license at all is posted, this isn't a right to copy or derive works, there is automatic copyright on the works.
E.g. If you post something under a CC attribution license, and someone shares it without attribution then they are breaking copyright, not breaking the license. They aren't licensed.
On the other hand, if no license at all is posted, this isn't a right to copy or derive works, there is automatic copyright on the works.