No - for reasons I'm not going to share with you - I have very good reasons for noticing that "things" changed on 11 Sep 01. However, I'm still a little bewildered as to how you think anyone knowing how a transponder is operated is going to compromise anyones security. After all, the entire system is, by definition insecure - ie Unclassified. It must be or else you wouldn't be able to obtain a transponder and you certainly wouldn't be allowed to leave one in an aircraft which can be opened with a piece of bent wire, parked on an unlit and remote aerodrome overnight. (The significance being, that the ungodly could simply remove one from a parked light aircraft and be away. Pick the right aircraft and the theft might not be noticed for weeks. They could simply take it home and stick it on a test rig - presto!)
Your assertion that "The operating details for aircraft systems are made available to all those with a legitimate need for them in the course of their training." is risible. If proof is needed, have a look at this -
http://www.caa.co.uk/docs/33/SRG_GAD_GASIL1OF2004.PDF - the item you want is at the bottom of page 6. Interestingly, this chap didn't know what the A prefix meant, nor did I until I started researching it. I don't know how I'd have reacted to the instruction either, and it's now over 20 years and 650 flying hours since the CAA issued me with a PPL. You may also like to have a quick peek in the Private Flying forum - you'll find a number of threads which are somewhat critical of how flying clubs/hour building instructors teach (and what they teach). I can show you a number of other GASILs, all of them telling tales of a lack of knowledge. If you'd like a quick look, try here:
http://www.caa.co.uk/publications/publications.asp
Bearing in mind that I can - subject to being able to afford the landing fees - take my Warrior into virtually any UK aerodrome including some handling international flights, don't you think that if I don't know how something operates or think I need further information to operate safely, then it's beholden on me to obtain it?
History indicates that the only time that you have all the information you should have had is when you read the report of the Board of Enquiry. If you're very unlucky, it's when St Peter debriefs you.
May I say that I find Blacksheep's comments about RPGs in aircraft both distasteful and offensive in an aviation forum.
Finally, thanks to all those who have taken the time and trouble to post and broaden my knowledge.