The annoying thing is GA pilots who have a transponder equipped aircraft but choose to use it on Mode A only, not C. Some say: "But that's what my (200 hour TT) instructor told me to do...!"
Reminds me of all the school aircraft I've flown with mode a/c and "NO ALT DATA" placards!
There are also those of us that leave the transponder off entirely.. and for good reason. Somehow we're still alive.
