If Subway lied in an objectively verifiable manner (as opposed to on a subjective/gray-area claim), they'd also be breaking the law. For example, if they told their customers that a certain sandwich had 6 oz of meat, and it in fact had 5 oz of meat, that wouldn't be legal. If they told their customers that their credit card transaction data was not being resold, and in fact it was, that wouldn't be legal. Facebook is alleged to have done the latter, among other things.
