The "calypso" script included in cardpeek can read the content of Navigo cards used in Paris. It provides enhanced "event log" analysis notably with subway/train station names, as illustrated in the screenshot above. It has been successfully tested on Navigo Découverte, Navigo and Navigo Intégrale cards.
You must use the contact interface to read a Navigo card (or a special contactless reader), because they cannot be read with a normal conctactless card-reader (these cards use a specific protocol that is not fully compatible with ISO 14443 B).
These transport cards keep an "event log" describing at least 3 of the last stations/stops you have been through. This "event log", which could pose a privacy risk, is not protected by any access control means and is freely readable. Note however that your name does not appear on the card (to our best knowledge), as opposed to the MOBIB card in Brussels.