Edward Hasbrouck in his The Practical Nomad blog has very detailed, informative, yet practical article on Europe reconsidering rules for reservation systems. While the article written in 2007, it has some interesting notions on privacy of travelers, of which many are not aware at all. He starts with explanations on what are CRS's, and what do they do. Then he goes on why were CRS's regulated and what did the regulations require. And here is interesting quote
Violation of the privacy clauses of the EU regulations is near-universal and completely ignored by the EC.Rest of article goes on why and how are CRS regulations changing, do the European regulations matter only in Europe, what will happen next and what should be done about that. And the other nice quote
The elimination of CRS regulations in the USA, and their reduction in Canada, makes it more important than ever that the EU retain its constraints on the demonstrated propensity of global CRS companies to engage anti-consumer, anti-competitive, and privacy invasive actions.
Edward is also author of The Practical Nomad book.