is right. However, it is too late to do a site-wide policy IMO, because it would be retroactive (i.e. would cover previously posted code without the authors' permission). So the best we can hope for is that monks optionally define the license with code posts or add something like this to their homenode:
, all code authored by "$code or die" on perlmonks.org is free software which you can redistribute and/or modify
Which /me is about to add to my homenode. You should be able to negate this license on individual code posts.