The concept of infrastructure related to the smart cities is being used to highlight the physical or social structures together with all the facilities that support the activities of a city helping it being functional. The concept itself refers to roads, railways, access points, buildings, distribution chains, water pipes and electricity lines, and, of course, digital networks. The article is focusing on the connection between the physical infrastructures with the digital ones, presenting, next to a bibliographic research made by the author, few technical solutions implemented successfully in the IoT field of development. In the same time there will be analyzed one of the biggest risks associated with the IoT, and that is related to privacy and security, risk that, due to the exponential growth of the numbers of equipment’s that are nowadays connected to the Internet along with the reduced time left for the developers to release a new product, they are bigger and stronger. The vulnerabilities once discovered do allow hackers to infect the system causing damages that are very difficult to handle – and, like hackers are not enough, governments, as well as marketing companies, are also threatening our privacy.