General knowledge about surveillance systems are limited to home or business use of covert CCTV systems and movies where stars take the role of intelligence agents in a high security operation. Little do people know that there are actually many surveillance techniques around that have been used for over centuries now far beyond the reach of our imagination. The use of a spy camera or a dvr or bugged devices is only a small part of it. This article lists the different kinds of surveillance techniques that are currently being used.

Computer surveillance systems monitor data and internet traffic via automated Internet surveillance computers that combs through immense amounts of intercepted data to recognise particular trigger keywords or key phrases, visits certain kinds of internet sites and interacts with distrustful persons or groups through electronic mail or chat. Realise that this has to be done through automation because there is just too much data transmitted on the web for human investigators to be able to achieve this. In the United States, bureaus like the Information Awareness Office, the National Security Agency and the Federal Bureau of Investigation disburse billions of dollars every year to develop and utilise systems to be able to capture and analyze all of this data so only the relevant information are extracted and reported to law enforcement and intelligence agencies. Personal data stored on computers can also be tapped into with the use of particular software.

In telephones and mobile phones, the tapping of lines is common. Speech-to-text software is utilised to transcribe calls to machine-readable text that is processed by automated call-analysis programs by searching for certain keywords or key phrases. In the United Kingdom and the United States, law enforcement and intelligence forces have technology to remotely turn on microphones in mobile phones to listen in on conversations that happen near the person who has the phone. Similarly, mobile phones are also utilised to collect location data that should really not be a surprise with the now common use of GPS and geotagging applications.

Aerial surveillance is the act of accumulating visual imagery or videos through a flying medium. Technological advancement has contributed to the development of aerial surveillance hardware that is able to recognize items at tremendously lengthy distances. In the United Kingdom there are already plans to build a fleet of unmanned aerial vehicles or UAVs to be used by police forces all over the U.K. These would range from micro-aerial vehicles or MAVs to full-size drones. MAVs do not only have surveillance capabilities but can also carry stun guns or weapons in certain events such as crowd control. There are already companies that have developed programs that automate aerial surveillance processes. These systems consist of fleets of drone planes that can automatically recognise suspicious persons and can decide the method on how to observe them. They also synchronize their actions with other drone planes close by and alert human operators of suspicious activity. As a result, the need for human operators will be much less because these fleets can continuously cover larger areas.

The use of a surveillance camera is the most common technique known to man because it is readily available to virtually anyone who can afford it and does not warrant a permit to utilise it. Whether the cameras are overt or covert, both do their jobs in observing an area by recording footage via a dvr. A spy camera can come as a pen, a car key, a watch, a pair of sunglasses and virtually anything that would look normal to an average person.

There are plenty more surveillance techniques that can be discussed elaborately but these are only a few systems that can attest that they are not only limited to home or business security systems. That is just the most common technique used because of ease of use and affordability. This is only a testament of how powerful it can be as a tool if used for the right reasons. But, as with anything technological, criminals may also utilise these kinds of techniques for unlawful activity. Only, their lawful counterparts are far more advanced in systems that they use to intercept criminal activity and to help peace and order prevail. So use them in the right conscience and for the right purposes.