HRV has had to pay out $400k (opens new window) for bad claims it made about its water filters. The interesting thing about this case, in my opinion, is that the fine was given because it was shown that HRV didn't have the evidence for its claims when it made them.
This idea can also be seen in the Advertising Standards Agency's rules - the idea that it's not good enough when challenged by an accusation of making claims without evidence to just go out and find evidence, but that you need to have had the evidence in front of you before you made the claims in the first place. This sets a high, but fair, bar for advertising, and it's good to see it being used to keep a company with a bad track record for misleading consumers in check.