Until the afternoon of Saturday 30 June, 2007, Scotland seemed to have little to fear from terrorism - but the attack on Glasgow Airport's main terminal building changed that forever.
BBC Scotland's Politics Show
The Glasgow Airport attack was carried out at the main terminal
Before then, invoking special powers to stop and search under the Terrorism Act was rare.
These allow police to approach people without needing to show that they have "reasonable suspicion" an offence is being committed.
From July, Scotland's eight police forces and the British Transport Police applied for and were granted the powers in Scotland.
Between them, the Scottish forces stopped and searched a total of 135 people and vehicles. None of the Scottish forces reapplied for the rights after they expired 28 days later.
The British Transport Police have continued to use them in Scotland and, since July, they stopped and searched a total of 14,620 people and vehicles.
This difference may seem large, but the transport police said it was small in proportion to the 75 million people who use Scotland's railways every year.
Supt Ronnie Mellis, British Transport Police area commander in Scotland, said: "The terrorist threat level just now is set at 'severe' for the transport infrastructure in the UK. We're not doing it for no reason."
According to transport police figures, 14% of those searched were from a non-white background - a cause for concern among some community leaders.
Osama Saeed, of the Muslim Association of Britain, claimed the number of stop-searches carried out on black and Asian people had increased in recent years - but Scottish transport officers said they had not received any complaints related to these concerns.
Mr Saeed said: "Since the Glasgow Airport attack, in Scotland, the same thing is being seen here. It's bound to lead to tensions between police and the Muslim community."
Transport police said they were facing a severe threat
Transport policing crosses borders and police representatives said it required a different approach to civil policing.
Joe Grant, of the Scottish Police Federation, said: "I don't think its an overzealousness. It's a response to the inability to make security a common feature at every train station."
Transport systems are vulnerable - as shown by the 7/7 attack in London.
Former Scotland Yard commander John O'Connor said that, because the transport system was a popular target, there would be increased transport police activity.
"Quite clearly, their strategy is to intensify their stops and searches," he said. "It doesn't make anything other than sense."
The Association of Chief Police Officers in Scotland said that stop and search powers were sought in the most extreme circumstances when there was a "specific operational need".
"The balance between the rights of the public to go about their lawful business and the need to protect society from terrorists are taken into account," said the organisation.