Hidden camera is known under different names – spy camera, surveillance camera. Wired or wireless, it is a devices only several millimeters in size, which is installed and launched without other people’s knowledge. As a rule, they are used for surveillance or entertaining purposes. Hidden cameras usage has its pros and cons. While providing personal security, hidden cameras also raise privacy issues. Thus, it is important to remember about legal regulations and restrictions before installing one. Lately, hidden cameras have become more popular among security companies as cost-efficient devices, which do not require much efforts for installation. Some of surveillance cameras have audio capability, so they are able to record sound, too. Regardless of the type and basic features, surveillance cameras also need a memory card or alternative data storage medium, so everything that goes on gets recorded. Otherwise, it is possible to watch what is going on only in the real time.