With apologies to Pronto who is probably just another innocent young fellow.
I have a healthy suspicion of people wanting to know how things such as transponders are operated. Those who need to know have access to the relevant documents and/or training. There has to be a doubt as to why anyone else would need to know whether or not you need to enter a Mode A squawk into a mode S system. Fortunately the reinforced cockpit doors keep people armed with anything less than a rocket propelled grenade outside.
This is a public forum and these days we must all learn to think 'security'.