I always find it a bit frustrating you must not take any liquid past a certain point.
But past that point there is vast amounts of liquids in different varieties for purchase.
Do they really test all these bottles? a overpriced bottle of volvic from the several WH SMITH's inside the airport? Do they test them? Do they?
I suppose a terrorist could get into the Evian factory and substitute liquid bang into a bottle, but then his mate at the airport might have to buy an awful lot of spring water before coming across the correct one.