For years, social networks have been responsible for enormous production of data exchanged on the network. The number of people connected to social networks has changed over the years and their habits connected to them as well. The Polytechnic of Turin used passive probes to capture internet traffic for 5 years, from 2013 to 2018, collecting 218TB of compressed TCP log data relating to connection flows to a central node of the network in Italy. The main topic of this thesis work is to isolate and analyze this logs to find out how to define a heuristic able to group user flows to Facebook in sessions and then analyze these sessions to understand how the amounts of data and habits of users towards Facebook have changed over the years.