I think the answer to this question is simple.
Apply the following rule:
In the spirit of Amateur Radio, can the conversation, in whatever format, be monitored simply by purchasing a radio (and modem, if a digital mode) and tuning to said frequency to hear said conversation?
If not (ie, you need to know the code to descramble, etc) then its not within the paramaters established by FCC rule (ie, we are self policing) and shouldn't be allowed.
Not that I want to hear everyones conversations, but if we truely want to be able to be self policing, we have to be able to be able to basically do that.
If I can't buy a D-Star radio, tune it to the output of the repeater, and hear the conversation then something is wrong. Same thing applies to any other mode. Including winlink, and other modes similar. If it takes more than 5 hoops to jump through to be able to police it, then its probably too complex to fall under the rules.
Besides, the simple fact should remain. BECAUSE of the fact that the FCC says we are self policing, ANY use of ham radio should be assumed to be in the public realm and monitorable at any time. If you have an issue with that and your answer to that is to do something to make it private, you shouldn't be using ham radio, you should be using a private service. You can make all the excuses in the book, but if you want private conversations, don't use an open and self policing service, and don't expect the FCC to bend it to be such a service.
Stuff to make it more flashy and cool I'll buy, but anything used to purposely obscure that can be done with a pay service....I don't agree with.
Course, this can be debated till we're blue in the face, but I ALWAYS assume that if I'm keying a PTT, sending an APRS packet, or anything like that, that someone is not only seeing it, they are listening......and taking notes!
WARNING: My wife says I'm the worlds largest source of natual gas. Shes right!
435 Repeater Audio: http://www.kd6nig.net/435rep.html