The BBC, perennially careless on language issues, incorrectly states here that radio talk show host Jon Gaunt was disciplined by Ofcom (the UK communications regulation authority) for calling a local councillor a Nazi. The error is repeated by The Times here, and by The Independent's headline here (and there may be many more). They misreport Gaunt's alleged offense. As the BBC article reports further down the page:
The pair had been debating Redbridge Council's decision to ban smokers from fostering children when Mr Gaunt called Mr Stark a "health Nazi" and an "ignorant pig".
I don't know the extent to which "ignorant pig" was the issue, but I do want to point out that "health Nazi" is not to be equated with "Nazi". The longer phrase evokes the bad-tempered and bossy lunch counter boss in Seinfeld — the one that they referred to with awe, though only when out of earshot of the awful man, as "the Soup Nazi".
Calling someone a health Nazi strikes me as a semi-jocular (if rather abusive) way of accusing him of foisting his health ideas on others in an authoritarian way. Gaunt wasn't saying that the councillor was a card-holding member of the National Socialist party.
Gaunt was fired from his job for the remark, even though he apologized for it later, and that is bad enough (he is now trying to take Ofcom to a court of appeals after it upheld the complaints against him). The UK has nothing like the protections for free speech that the USA has; in the communications industry especially, you can lose your livelihood for an epithet. But things are made even worse when jocular phrases like "soup Nazi" are confused in media headlines with serious allegations like being a Nazi which are arguably actionable defamation.
The Seinfeld characters were tagging the Soup Nazi in the sort of way an insulting cartoon would do. They weren't making a defamatory claim about his political affiliations. If we lose track of a distinction like that, the appallingly draconian and restrictive the communications regulations and defamation laws in Britain will be even more dangerous than they are right now.
[Actually, there's bit more to it, because as Ian Preston reveals in a comment below for which I thank him, Gaunt also used the word Nazi without its modifier before he went on to use the phrase health Nazi immediately afterward. But he claims that was just a slip, and health Nazi was what he meant throughout. —GKP]