Living sustainably is not easy for urban families. This mixed method collective case study looks to explore the development of habitual ecological action in families living in an urban setting, a context of socio-ecological transformation rarely examined in social science and environmental education. Given the ever-increasing popularity of social media today, this study seeks to understand the potential role of Facebook in promoting environmental action and to compare it to the use of e-mail as an Information and Communication Technology (ICTs) for the promotion of environmental action. In other words, for families already intent on living sustainably, we are interested in understanding how the use of social media could help bridge the gap between intent and action, as compared to using less network-oriented ICTs, such as e-mail. We recruited 45 families from two cities and divided them into two distinct groups. The first group of families attempted to lower their household electrical bill as part of a private Facebook group, while the other group aimed to do the same, but via e-mail instead, i.e., without the directed use of social media. For both groups, we compared the quantity of kilowatt-hours used during the project to those used for the same months in the previous year, adjusting for temperature variations from year to year. Our analysis of descriptive data shows that both groups experienced lower electricity consumption during the project months. Exit interviews help to explain these results and point to a better understand of eco-citizenship development as a process in the context of family. Our qualitative results suggest that family engagement and child participation seem to be higher in families interested in living more sustainably when these families are part of a social network.