In IoT division, we perform regular analysis of smart devices aimed at obtaining as much sensitive information as possible, or at compromising and misusing the tested device through further attacks. Security testing includes smart light bulbs, cameras, televisions, alarms, and sensors. More complex devices are no exception, such as various industrial automation equipment or smart cars. Knowledge obtained from the analysis of these devices can be used in Industry 4.0 and Smart Cities, which will constitute critical IT infrastructure in the future. The aim of these analyses is to inform the Czech and foreign public about the vulnerabilities of IoT devices, to demonstrate how easily they can be misused and what the consequences may be. We pass on the experience gained to our clients.