Should we hold scientists and journalists liable if they say false things or misrepresent things?

We already do. Libel and fraud are already illegal.

Yes, obviously.

If they do so knowingly, and harm is caused, then yes. Are you suggesting we should give them a pass from years of acquired jurisprudence simply because they hold a particular title?

And what institution gives out the licenses for journalists and scientists? Is it revokable?

You don't?