Even after several E-Mails SONY does not want to react on this case. A short summary of the violation:
SONY did release "Facebook for PlayStation VITA" several months ago. SCEE is listed as developer/publisher of the software. Once you have downloaded the app, you can view it's licenses by clicking the "?" tab in the mainscreen of the app.
A screenshot collection of those can be found at:
Inter alia, here you can see that the open source software "Webkit" is used which is licensed as LGPL software. Like PlayStation Mobile, the PSV Webbrowser and some other software, SONY has to provide the source code of the modifications made to the LGPL software.
Normally SONY publishes source code which they are forced to share at http://www.scei.co.jp/psvita-license/, but as you see the Facebook app's Webkit source is missing...