They use these kinds of transponders for TCAS (traffic collision avoidance system), so yes, it should be plain text if you like planes not crashing in to each other...

Isn't position and velocity (and acceleration?) enough for TCAS? Why do you need full identity and flightplan for the aircrafts?

If I'm in a plane that is being controlled through a TCAS input, you can be damn sure I'd like anyone on the ground at all to know that I am in that plane.

The reason is: planes are a life-threatening situation. You cannot live in a plane. They are a temporary place in which you must park your body during periods of extremely high risk.

If two planes crash, because: IT HAPPENS, then not having to decrypt the flight manifest to determine who was on the plane, is a mighty fine use of public force, i.e. law-making.

I care not a fig for someones' privacy, if it means life-saving activities have one less layer of human cruft attached to the process.

If you're coming to find my body on the side of the mountain because I was unfortunate enough to hitch a ride with my rich millionaire and his drunk pilot, please know exactly who I am, and how to contact my immediate family, in case of my demise.

I guess we'll have to agree to disagree. I feel very strongly that if one wishes to get away for awhile and not tell the world where you are heading then you should very much be allowed to do that.

For that argument from privacy to work you need to provide reason for why flying is the only acceptable form of travel. Or why it is only acceptable to "get away" to locations to which flying is the only possible means of travel.

Realistically speaking, the only traveling you can do with perfect privacy is that which you do without involving others. If you use a travel service your desire for privacy becomes an imposition on the free speech of others.

Its exactly analogous to refusing to ring your fog bell on a boat while stuck in a fog bank, or refusing to use turn signals on a car.

It's not at all analogous. A turn signal tells the people around me that I'm just about to turn, not that I'm on a road trip from Chicago to Tucson. Nor is my entire turn signal history centrally logged and searchable.

There are two analogies:

- The broadcast of your location data is analogous to a turn signal.

- The FR24 community is analogous to a group capturing data about use of turn signals at various intersections and aggregating them.

Both are perfectly reasonable analogies.

And yes, it's completely possible for people using only publicly-visible information to put together your entire turn signal history and make it searchable.

I think the problem is that some of us aren't up to speed on the particulars. Is that what's being blocked (and proposed for encryption)? Just the "full identity and flightplan"?

Flight history of blocked aircraft is inaccessible as well. E.g. executives may not want to reveal insightful flights.

E.g. American Airlines AA1 recent flight history: http://www.flightradar24.com/data/flights/aa1/

Sure, but why should we be biasing the maintenance of a corporate advantage here?

Because the intention is to migrate air traffic control systems to the use of ADS-B data to replace or augment Secondary Surveillance Radar.