I once listened to some german guy on London Info who was right at the Dutch/UK boundary at FL105 (well inside the airways) asking for a direct Jersey through 'his' airspace, VFR. Even before London Info could reply he was well into UK awys.
London was very polite but this prat was extremely reluctant to descend out of the airways, and seemed to be of the opinion he had a god given right to fly where he pleased.
I really hoped he got the book thrown at him.
NATS get very frustrated by people who turn off their transponders or to just Mode A when they think they are getting close to airspace, and this too could evoke a less than sypathetic approach by the enforcement branch in the event of an infringement.