PLT OF C172 MAY HAVE BEEN AUTH TO SQUAWK VFR PRIOR TO DEPARTING THE DC ADIZ.

Narrative

WHILE ON A VFR FLT AND ADIZ CLRNC EXITING THE BALTIMORE/DC ADIZ AT 2000 FT MSL; APPROX 27 NM ON THE BAL 140 DEG RADIAL; STRAIGHT AND LEVEL FLT; I WAS NOTIFIED BY POTOMAC ATC THAT I WAS CLR OF THE ADIZ; SQUAWK VFR AND FREQ CHANGE WAS APPROVED. I ACKNOWLEDGED AND SQUAWKED VFR BUT STILL CONTINUED TO MONITOR POTOMAC ATC AND 121.5 MHZ. NO FURTHER XMISSIONS FROM POTOMAC WERE DETECTED. I CONTINUED ON MY HDG OF 140 DEGS. I XCHKED MY GPS DISPLAY; AERO CHARTS AND VISUAL REF TO THE GND TO CONFIRM THAT I WAS OUTSIDE THE ADIZ. I THOUGHT THAT POTOMAC ATC MIGHT HAVE CLRED ME TO BE OUTSIDE THE ADIZ TOO EARLY; BUT WAS UNSURE AND COMPLIED WITH POTOMAC ATC INSTRUCTIONS NONETHELESS. A THIRD PARTY GOV AGENCY (UNKNOWN AT THE TIME OF THIS WRITING) WAS ALSO MONITORING THE AIRSPACE AND THE FAA HARRISBURG FSDO IS NOW (+5 DAYS AFTER MY FLT) INTERESTED IN 'TALKING TO ME ABOUT MY FLT.' WHILE I HAD COMPLIED WITH ALL ATC INSTRUCTIONS (ATTAINED A PREFLT BRIEFING; FILED ADIZ FLT PLAN AND FOLLOWED DEP INSTRUCTIONS); IT APPEARS THAT IF ATC MAKES A MISTAKE; THE PLT IS TO BE BLAMED FOR COMPLYING WITH ATC. IT IS ALSO INTERESTING TO NOTE THAT ON A RETURN FLT THAT SAME DAY; THERE WAS NO MENTION OF ANY PROB EARLIER THAT DAY BY POTOMAC ATC.