If the scope of it is as described I can't see how anyone s would think its a good idea, even if they support the general principle behind defamation laws and assume the internet works the same way as any other form of publishing. Unless they happened to be a public figure constantly in the press for consorting with prostitutes etcetera, of course.

If its scope is as described in the Wikipedia article it's akin to forcing newspapers to follow up every front page Berlusconi expose with a front page statement from Berlusconi that it didn't happen. Would the Italian public stand for that?