Gosh. The Ryanair guys are well-known for public posturing that seems a LITTLE bit too extreme to be taken seriously just so they can get press, but this set of e-mails almost sounds serious.
You can't just go threatening to sue people because someone posted defamatory and hard-to-prove things about your airline in their blog's comments page! That would be madness (and some of FlyerTalk's airline forums would suddenly get very, very quiet).