I am curious, what did they ask her to do and who asked?
Is this BAA Security?
Was it random or was there cause for suspicion?
Was she permitted to be searched by a woman and in private?
Why was she stripped to her bra?
At the time, the Security Alert state was "Severe" - indicating a terrorist threat against Britain was likely. As part of the "severe" state, BAA Security staff are under strict instructions from the Department for Transport that any "activation" of the security archway must be reconciled.
As regular travellers know, if you "set off" the arch, apart from a random check (which if you're quick you will see the word "QUOTA" appear above the archway), the staff will wave a wand over you until they find the metallic stuff (usually a watch or jewellery) that's triggering the alarm. The wiring in a brassiere can set the alarm off, but staff can usually tell from the way the wand behaves if that's the case or not.
In the case of the staff member, the wanding did not produce a definitive answer for security so she was asked to strip in the presence of as female BAA manager and a BA manager.
Unfortunately, while no one can force one to be strip-searched, entering the "Restricted Zone" is considered voluntary and, by entering into the search area, one has "voluntarily" give one's consent to co-operate with any searches required under powers given by COBRA, Transec or DfT.
BBC NEWS | UK | England | West Midlands | Clown strip-searched at airport
At the end of the day, one can make a complaint to the BAA management or higher if needs be., However, I have never had a problem with the security staff at all (apart from one over-familiar encounter in Terminal One about four years ago. The nasty little character later lost his job after a number of complaints.)