I've always said this, there should be a penalty and I'd go for longer than 24 hours. Three strikes and you're out from broadcasting for 48 hours seems fair to me if they repeatedly flout the truth. And if they continue then their licence should, as you've said, be revoked. This is the problem with the ASA - no teeth, and organisations like Gemporia know it. Twas ever thus, and no sign of it changing.
