Balloonslayer the problem is that this is very much a grey area - most websites will carry a copyright notice like ours - but it doesn't necessarily mean that it's enforceable - much like the libel laws and how the law views internet publishers it's a moving target and none of it has been thoroughly tested.
As said we're looking into what the very latest thoughts are on this and let you know. We'll also update our copyright notice today as we've intended to do for sometime - I've found the stuff that was on someone's to do list - after the last discussion about this.
RE not objecting to the DM lifting stuff as said that's because it is our understanding that they are within their rights to do so as this is a public forum but again, we will ask the inestimable Mark Stephens what he thinks and get back to you.
I'm sorry if you think we're being slack. All I can say in our defence is that we are not over-endowed with resources at MNHQ - part of the downside of not being overly commercial (which I think is what most Mumsnetters expect of us) is that we aren't raking huge amts of dosh to pay for lawyers, administrators, etc.