UNITED STATES airports have begun checking all luggage bags for explosives causing a slowdown of passenger throughput but not the massive disruption predicted in some quarters. As of midnight 1 January 100% of bags were being checked for explosives, more than 90% of them electronically, dramatically up from 5% before the 11 September attacks. Those not screened by machines were being gone over by hand or by bomb-sniffing dogs, or matched to passenger lists to make sure travellers who checked luggage actually took on their flights. In the UK similar procedures have been in place for some time, passengers now very much used to allowing more time for checking in. Reaction in the US seems to have generally been philosophical.