After reading the posts to date on this thread. I think people need to take a step back from what the company Ryanair is communicating and what Darren in HR is communicating on behalf of Ryanair.
Darren in HR in this case is only doing his job! Some individuals on this forum need to get over it. Recruiters in all industries message staff over LinkedIn not just the aviation industry. That is part and parcel of recruitment. If you don't like the message ignore it, don't reply to it, delete it etc.
I don't like the way Ryanair treat their staff anymore than anyone else but I think some of the comments on here are disrespectful towards the individual in HR who is just doing his job at the end of the day.