XBL Question

 Had a major glitch with the XBOX 360 early hours of this morning that some of you may have heard me speak about already elsewhere on the forum, lost most of my own livery designs and tunes, many of which I hadn't even revealed or used yet, lost all of the tunes and liveries I was creating and partly finished for other people but what was strange is that this glitch, whatever it was, reset every XBOX setting to default, removed almost all various game save data and wiped my entire XBL friends list as well which I was always led to believe was stored on Microsofts servers, anyone know or able to confirm that XBL friends list is stored on MS servers?