English/pages_MacUS/wls_set_content.html on the Canon MG3100, MG5300, MG6100, MP495, MX340, MX870, MX890, MX920, and MX922 printers shows the Wi-Fi PSK passphrase in cleartext, which allows physically proximate attackers to obtain sensitive information by reading the screen of an unattended workstation.
http://www.mattandreko.com/2013/06/canon-y-u-no-security.html
http://archives.neohapsis.com/archives/fulldisclosure/2013-06/0146.html