The internet, whether one likes it or not, has become one of the principal means of access to scientific and non-scientific knowledge. The mechanisms regulating the dissemination of facts and information online are complex and partially unknown. For some of them, such as confirmation bias and polarization, specific mathematical models have been provided. Although a lot of work still needs to be done, it is already possible to develop strategic behaviors aimed at countering disinformation. Anyone who works in the medical field or in science in general must not ignore these themes, because they are likely to become the foundation of future health communication and reliable scientific knowledge distribution online.