There are many types of surveillance equipment available. There are setups that are obviously made for observation, and then there are the less noticeable apparatuses. Observation can be done by anyone from private homeowners to businesses to government agencies; and for any number of reasons.
Perhaps the homeowner will set up surveillance equipment to observe the activity in their home when they are not present. There could be a number of reasons the homeowner has decided to do this. The most compelling reason for many is that it will deter thieves. If it does not deter them, then at least there is a way to possibly identify the criminal and solid evidence against them. Another plight of the individual might be to catch a spouse who is suspected of hiding something such as infidelity. On the other hand, maybe a couple is worried that the babysitter is not quite paying enough attention to the baby, or even worse, neglecting him completely. This homeowner could choose to use an outdoor videoing system, a ‘nanny-cam’, a wired (or wireless) hidden camera or a number of other sound and video capturing devices that are available for purchase.
What about the business owner? Over fifty billion dollars each year is tossed out the window on office supplies stolen by employees. Okay, it is not literally tossed out the window, but it may as well be. The employee that thinks it is okay to snag the occasional manila folder or ball point pen does not stop to consider the cost of that theft. And, yes, it is THEFT. It may not seem like much, but now consider what would happen is every single employee in a company of 500 people took just one manila folder and one pen each month. That translates to thousands of dollars a year! Now, throw in the occasional bottle of correction fluid and the gutsy soul that walks off with a calculator. The losses just keep getting bigger and bigger. That alone is enough to make a business want to implement a surveillance equipment system. An employee is a lot less likely to take office property is they know they are being watched. The thought of being observed is also likely to increase productivity as the employee will not want to be caught chatting at the water cooler instead of working on a presentation.
As far as government usage of surveillance equipment, it is beneficial to our entire country in many ways. It is used to increase public safety and deter criminal action. It is also used to track known or suspected terrorists, in addition to many other things.
Audio and video surveillance equipment is available in many forms. You maybe be able to make local purchases, although your biggest selection of items will be at an online retailer. You will be able to find anything from full scale setups for thousand acres properties, all the way down to micro technology that is as small as a pin head. You might be surprised at some of the technology that is available to the average consumer!