At the moment Safari has the document.domain property defined with configurable set to false. ([Unforgeable] in IDL.) Should we adopt this in the specification or just leave things as is?
It's been suggested some sites might rely on document.domain being trustworthy, though I don't have data for that claim. (In other news, Object.getOwnPropertyDescriptor(document, "domain") does not work in Gecko or IE10...) -- http://annevankesteren.nl/
