Mal Fletcher comments on the use of CCTV cameras and Tesco's announcement that they will soon be using face detection software

Even for the more scrupulous corporate entities, there is the danger of future material being stored and then stolen and misappropriated.

If highly developed national governments have proven unable to guarantee the security of their databanks, why should companies be trusted with data that could be used by others in unintended or as yet unforeseen ways?

That's especially true when we consider how quickly technology is moving ahead.

Basic technologies already exist that, if fully utilised, allow law enforcement authorities not only to track crimes but to automatically mete out punishment, without the involvement of a single human being anywhere in the process.

Some countries are experimenting with these tools in dealing with traffic offences.

This may sound like sci-fi to some, but wifi was sci-fi not that long ago.

The biggest problem with using potentially intrusive technologies in ways that were not first mandated - or at least expected - by the public, is that it erodes trust.

The UK has around 61,000 CCTV cameras, more than any other European country per head of population. Some reports have the total at around one camera for every 1000 people.

Intriguingly, a 2009 study conducted by the BBC showed that some of our tiniest regions have more cameras than much larger cities elsewhere.

For example, two of the smallest local authorities in the UK - the Shetland Islands Council and Corby Borough Council - have more CCTV cameras than the entire San Francisco Police Department.

According to the same study, the City of London has 619 cameras, but a population of only 9,000. That's 68 cameras for every 1,000 people. The London borough of Wandsworth has more cameras than the police departments of Boston [USA], Johannesburg and Dublin City Council combined.

During the recession, some local councils were reportedly forced to turn off some of their cameras. These units are not cheap to maintain - and they require an army of paid officials to view and process their 24/7 data-feeds.

Whether operational or not, however, the units are left in situ, in plain sight. So even when they're not working, there is no appreciable gain in terms of public perception.

And it is public perception which ought to be the biggest concern for governments and companies looking to extend the use of CCTV technology.