OK, this is purely your webmaster's opinion...but tell me I'm wrong:

Those of us who grew up around the WW-II era watched innumerable movies that showed cowering travelers having their "papers checked" by totalitarian authorities who had unfettered authority to haul away anyone for any reason.  We felt so very superior to these poor unfortunates because we lived in the United States, a 'free society' within which we could travel as we wished without permission from State Security.

Fast forward to 2009 and guess what?  We're in the movies! 

Under rules that became mandatory in May 2009, we and anyone else flying with us must have our "papers checked" and be issued a security clearance by Homeland Security for the flight  prior to taxi, if we are headed for Canada, the Bahamas, Mexico, etc.  The justification for this?  Homeland Security says that, unknown to you, your wife (or fellow Skypark resident, etc.) may well be on their top secret million-name "no-fly" list and cannot be allowed in an airplane.  I do not joke, this is exactly what they say.  As we know, this same 'no-fly check' already has been universally applied to commercial flights, and doubtless Security's empire-builders viewed general aviation as a quick and easy target for agency expansion.

To make this even more enjoyable, there have been several incidents (May, June 2009) in which pilots who properly filed the necessary request for security clearance via eAPIS, and received back the 'clearance to depart' from Homeland Security, were subsequently physically halted while preparing to depart. They were subjected to detailed and time-consuming searches of their aircraft, contents, and their own persons & personal belongings (wallets, purses).  In one of the incidents (Long Beach airport) the search involved numerous vehicles with flashing lights, agents with drawn guns "screaming" at the airplane's occupants to 'keep your hands on your heads', etc.  In no case was any explanation given beyond "this was a routine ramp check and you can go now".  Quite naturally, no terrorists, weapons, explosives, etc. were detected.

When Homeland Security was formally questioned about these incidents the response of a spokesperson exactly echoed that given by Nazi Germany's Geheime Staatspolizei (Gestapo). She said, in essence, 'we have the authority to do this type of search anytime we want to, you can expect us to do more of it, and we have no obligation to explain or justify our actions to you'.  This response, in my opinion, is even more scary than screaming agents with drawn guns, claiming as it does totally unfettered authority to do whatever they please.  The Constitution, which presumably is still somewhat in effect in America, flatly prohibits 'unreasonable' searches, and specifies that a warrant authorizing the search & seizure procedure will be issued only upon probable cause and shall describe  ".. the place to be searched, and the persons or things to be seized".  The Supreme Court has carved out some exceptions to this, such as permitting search by a police officer who 'reasonably suspects criminal activity' (and can later justify his suspicion to higher authority), but the above incidents appear to have been purely random in nature and therefore would be impermissible, IMHO.

Additionally, in February 2009 there is an incident in the news where TSA officials showed up at a Nashville FBO and started conducting bag searches and wanding crew & passengers headed for their private aircraft. They also checked FBO employees.  See the discussion of the Constitution's Fourth Amendment, above.  The agents referred to a secret document they call the "Playbook" as their authority to be conducting such searches. There seems to be some difference of opinion even within the TSA about this but since access to the authorizing document is not allowed on the grounds of national security, as a practical matter it can say anything they say it does.

Whether or not TSA will modify their stated intent to apply the full Monte of airline-style security checks to private aircraft flights within the USA is unknown at this writing, but we have already established that invoking the god of Security trumps all objection.  While current TSA manpower limitations dictate they start with 12,500 pound and larger aircraft, once it starts it certainly will not stop there, because the growth potential for the security empire is vast.