One of the latest ASA rulings was against Sky and in particular its Original Bundle with Broadband Lite. The Lite product is the free broadband service that Sky TV customers are entitled to in LLU areas and has a minimal 2 GB usage allowance.
BT complained about an advert, where Sky was highlighting the catch up TV potential of its bundle, and while they did qualify IPTV based catch up in the small print i.e. a 30 minute show would use 0.5 GB of data, the ASA has ruled that free usage allowance on the free product would 'significantly limit the amount of Catch Up content that could be downloaded extra to the selected content provided by Sky'.
Given the superlatives used in the current wave of 4G advertising, it can only be a matter of time before similar complaints are raised about the expectations the adverts are setting for what you can actually do. Or to put it another way, with Netflix now supporting HD films, one movie is likely to use up your whole months usage allowance, unless you are paying for a 8GB or higher allowance.