Distorted skewed priorities
Profit is the primary motivator for BAA shareholders and everything else is a hindrance to realise any such profit, including security.
T5 is a perfect example of how BAA misuses 'security' as means to increase footfall for the benefit of the retailers, of which BAA takes quite a large cut from every sale.
Dispatches on Channel Four discussed this not so long ago.
BAA is not even a British company - 85% of it (or there abouts) is owned by Ferrovial - a Spanish company.