This is what we have to understand. Microsoft stores this digital information on servers that THEY OWN. That means that if any child pornography or defaming naked picture is found on their property, THEY are liable.
If a friend came to you and said keep this on your property but don't look in it and the police came and searched your property and found that it was a nuclear missile, I don't think you could say oh but my friend wasn't planning on sharing it with anybody.