The US <a href="http://arstechnica.com/tech-policy/2014/07/ars-editor-learns-feds-have-his-old-ip-addresses-full-credit-card-numbers/">keeps
lots of information</a> about everyone's airline ticket purchases and
appears to keep it for at least 10 years.
Ссылка: https://stallman.org/archives/2014-may-aug.html#21_July_2014_%28Airline_ticket_purchases%29