Are people actually that OK with uploading their credit card details and passport numbers to an online server belonging to a very public company? Ryanair would be an attractive target for Cyber criminals.
With a supposed 200million pax count in a couple of years, that's what, 40 million individual passenger profiles? (Assuming repeat travellers)
I think it's mad to be storing all that kind of info on a server you know nothing about. Remember TKMaxx a few years ago? Their Irish arm was breached and all credit card details etc obtained. Tesco bank was breached just a few weeks ago and peoples current accounts frozen while Tesco worked out what happened. Ashley Madison this year, to name just a few.
This is absolutely for Ryanair's benefit only. Expect no assistance from them if and when they're breached.