Ultimately the fact finder at trial, just as in cases of fraud or defamation. But preliminarily often an agency, as with false advertising statutes. The govern

Ultimately the fact finder at trial, just as in cases of fraud or defamation. But preliminarily often an agency, as with false advertising statutes. The government and courts decide truth and falsity all day, everyday. That isn't new. The real issue is the scope of speech and activities that are put under scrutiny.