Just a question...
 

As it is now some years since I last flew in US airspace, I wonder if anyone can confirm a statement made by Meacher in a broadsheet today. He states that if (any) aircraft deviates from the F/P, fighter aircraft are sent up to investigate. Is this really the case?

Kinda Sorta, depending upon your proximity to certain areas and the amount of deviation, yes, you will be intercepted.

It depends! How is that for a definitive answer?
If you are near Crawford Texas when GDUB is there and you are VFR watch out! Always fly IFR and you will most likely not have any problems at all.
Enjoy flying in the states where you are still the PIC! If you have the money for the plane and gas and play by the rules you will enjoy what we have here that , saddly, has disappeared from most places on this earth, freedom!