Platoon formation is a freight organization system where a group of vehicles follows a predefined trajectory maintaining a desired spatial pattern. Benefits of platooning include fuel savings, reduction of carbon dioxide emissions, and efficient allocation of road capacity. While traditionally platooning has been an exclusive option limited to specific geographical areas managed by a single operator, recent technological developments and EU initiatives are directed at the creation of an international, federated market for platooning, i.e., a consortium of platoon operators that collaborate and coordinate their users to constitute freights covering international routes. In this paper, we look at federated platooning from an insiders' perspective. In our development, first we outline the basic elements of platooning and federation of platooning operators. Then, we provide a comprehensive analysis to identify the possible insiders (employees, users, operators, and federated members) and the threats they pose. Finally, we propose two layered, composable technical solutions to mitigate those threats: a) a decentralized overlay network that regulates the interactions among the stakeholders, useful to mitigate issues linked to data safety and trustworthiness and b) a dynamic federation platform, needed to monitor and interrupt deviant behaviors of federated members.