I've just heard that the police have arrested three people at Heathrow Airport under the Prevention of Terrorism act. Brian Paddick, the Deputy Assistant Commissioner of the Metropolitan Police, said it would be "inappropriate and pure speculation" to link the arrests to Thursday's attacks.
While I'm on the subject of speculation and airports though, there's a huge kerfuffle taking place at slashdot.org about a report from The Times newspaper saying that body scan machines will be used on tube passengers.
This report only came out the day after the attacks and as yet I've not seen it mentioned elsewhere. "Tube passengers are to have their bodies scanned by machines that see through clothing in an attempt to prevent further terrorist attacks. The millimetre wave imagers will be used to carry out random checks as people enter stations after services resume today."
It continued: "QinetiQ, the privatised former Defence Evaluation and Research Agency which developed the technology, said the scanners could be fitted to all 270 Underground stations within 18 months.
Each station would cost from �150,000 to �2 million to fit depending on its size and the number of entrances.
Simon Stringer, managing director of QinetiQ�s security division, said: 'We have been asked to deploy some of this equipment'."
Apparently conventional airport scanners are impractical of the level of passenger handled on the Tube each day - three million everyday. Philip Baum, managing director of the security consultancy Green Light, said
"there will be huge civil liberties questions because you will have to accept that people will see you walking round semi-naked."
He added that vigilance by passengers would play a greater role than any technology in detecting terrorists. I remember after last year's Madrid train bombings and after September 11th there was a much higher reporting of suspect packages and I'm sure the same will happen now.