Ryanair are an absolute bunch of bastards. I've flown with them as a result of having no viable alternative and sworn never again. The sooner the OFT clamp down on them and their unquestionably dodgy practices, the better. Their methods of charging follow no logic or reason (credit card charges etc) and stay narrowly within the bounds of the law. They have excellent lawyers who make sure they don't stray too far outside it while skillfully (and obviously with a calculated risk/reward equation factored in) do their best to screw the consumer.
May they get royally shafted by better quality airlines who don't treat their customers like an inconvenience.