This is a gap in security that pilots have known about for years. We should be pleased it has been brought to public notice, regardless of the motives of the driver and journalist, because that's the only way it will be put right.
To those who say this sort of breach is unlikely to happen for real because it requires the assistance of a passholder who has been vetted, how do you explain the large number of illegal immigrants who were recently found to be working airside at Heathrow and Gatwick? Had they been vetted? Don't confuse the cursory checks carried out on airport employees, including pilots, with serious security vetting.
It's irresponsible to say we should keep quiet about these failings to avoid alarming the public. They'd be more alarmed if real guns or bombs had been put on board with fatal results. If the BAA and others are not forced to answer for their neglect they won't put matters right.
Next time you're frisked at check-in, in full view of the passengers (shoes off to check for explosives etc), remember that the people responsible for it have been shown up for the fools they are. And smile.