We have all become used to the increasing prevalence of technology in our lives -at work, at the airport, in shops, and especially in our homes - so it is no surprise that the police have been subject to the same trends.

Technology has helped solve crimes; CCTV has helped convict murderers; and there is generally public acceptance of some degree of surveillance if it helps make society safer. What the police must never do, however, is take that acceptance for granted. Surveillance should also only be extended with the greatest caution, which is why the latest news about Police Scotland's use of facial recognition software is of concern.

Thanks to a Freedom of Information request by the Scottish Lib Dem MSP Alison McInnes, we now know that Police Scotland has used the facial recognition software on hundreds of occasions in an attempt to match faces captured on CCTV with those on the UK-wide Police National Database. Police Scotland has also uploaded hundreds of thousands of mugshots onto the database.

For Ms McInnes, the fact that Police Scotland has been doing this raises questions over the protection of civil liberties. She is worried that without adequate safeguards, there is nothing to stop the police using the technology for the mass surveillance of innocent people. In particular, she is worried that the police could identify people who are legally asserting their right to protest at political events. She is also worried about the potential for mistakes and that innocent people could be falsely identified and prosecuted.

All of these concerns are real and the Scottish Government must now explain how the use of the technology is regulated and what procedures, if any, are in place to ensure it is used appropriately at all times. Police Scotland has confirmed that the mugshots of people charged with an offence are routinely added to the database; they also say the photos are removed if a suspect is not convicted. But the fact that there is likely to be pictures of innocent people on the database when the software is used is worrying.

The obvious defence is that the database is helping to solve crime and that is an argument that many citizens, even those concerned about surveillance and privacy, will accept. There has always been controversy around the use of CCTV for example, but as the number of cameras has tripled in a decade, there has been some acceptance of their efficacy, with CCTV images providing significant evidence in a number of murder trials. Police Scotland has made the same arguments over the database and the facial recognition software, saying that searches have helped solve crimes. In one case, a thief was traced and convicted after a CCTV image of him stealing from a bookmaker's was matched with a mugshot uploaded to the national database by Police Scotland.

However, the efficiency of technology and its usefulness in detecting and prosecuting crime does not absolve Police Scotland and the Scottish Government from ensuring it is properly regulated and controlled, not least because the scale of Police Scotland's operation is so huge. To date, it has uploaded 601,837 custody mugshots onto the database, featuring 334,594 individuals. In a small country like ours, that is a vast advance into the area of personal privacy, however effective it may be in solving crime.

No one would suggest that the right of privacy means such a database can never be used, but it is now for Police Scotland to justify in detail why its current procedures are necessary and it is for the Scottish Government to explain how the process is regulated so that a discussion can be had about whether the regulation needs to be tighter. Police Scotland has been using facial recognition on the national database since 2014, but it is only now that we are becoming aware of the scale of its operations. Police Scotland says it helps to tackle crime; we must now be told what is being done to tackle any intrusion into personal privacy.