Burn Note

And we believe that the notes are 'burned' because ? ...

That isn't a snark, it's a real challenge. If you create a service which caters to 'burn after reading' levels of confidentiality, then one would assume that such a service would attract valuable 'secret' information which the owner of the service, if not legit, might exploit. While that does not seem to be the case here, its a fundamental challenge of building services 'in the cloud' that one is asked to trust with valuable data.

while the "spyglass" idea is nice, i'd prefer having at least some kind of client encryption in order to avoid the trust issue mentioned by ChuckMcM.

ZeroBin (http://sebsauvage.net/paste/) did an excellent job regarding that topic imo.

It's a great idea but I would be very open and transparent about the deletion policy for the notes.