In the past decades wireless networks have registered an enormous increase in their diffusion. It is very common to find many networks available when travelling because shops offer their private Access Points as well as private organizations and cities. Most of the networks are free in exchange of your personal data, many others are private and protected with passphrases. In any case, the need for people to use a connection instead of consuming their cellular traffic is very high and the majority have no idea of the possible security threats. In this scenario, there is a new attack surface to lawfully intercept investigated people that is explored in this thesis.