The PanAm games currently being held in Toronto had until very recently a ‘do not link’ term on its web page.
I do not understand why such a term would be enforceable. What legal right is asserted? Linking does not imply endorsement, as we know from defamation cases. Nor – so far as I know – does it constitute use of any trade mark in the URL linked to, by the person making the link. So – what?