Well, an implied contract *IS* an implied contract. It does not *always*
hold up in court, but there is no reason why a list owner/subscriber
should risk thousands of dollars to challenge that claim. That claim is
challengable but there's NO guarantee that you will successfully overturn
that claim.

> Yes, some lists claim to have rights to whatever is sent to them.  I don't
> agree with that and doubt they could maintain the claim, unless they
> textualy edit every posting, against a serious court claim.

On another note, I think whether the claim is challenged or not depends on
the material itself more than anything.

For instance, if you're say a Microsoft software engineer, and you posted
to a non-Microsoft technical mailing list, Microsoft could claim
copyright on the writing (because any software advice/idea belongs to
them when you work for them - depends on your contract), whether you're
using Microsoft's computer systems to write the message or not.