Re: That's a...
No, friends only isn't a "great solution". How exactly did you come by some of those friends with this filter set? If you feel you have enough "friends", then sure. However, what if it is your first day behind an Xbone?
This doesn't look attractive at all for the console, especially when you consider how much spam Microsoft has already ignored through the years with Internet Explorer (e.g. It took competition from Mozilla for them to even think about the word "security"). Factor in that they are already trailing behind PS3, this won't help (obviously :-/). However, at least Microsoft was ~active~ enough to publicly ignore the problem until they got through the holiday shopping season.
Oh, and as a PREVIOUS xbox 360 owner, I can tell you right now the security is dismal, laughable bad. You could at one point in time rewrite a file that was intended for "identity" and the "gamertag" in a certain way that you could jack anyone's account that you were in a game lobby with. BTW, this did _NOT_ require a modified console at a hardware level, only access to the FATX filesystem. Of course did they really care, because last I saw online "leaderboards" people were still ranked at the top with a fictitious score of somewhere around 2^99 (Maxed out double float values is what you saw).