One of the challenges of digital platforms is societal. GAFA [Google/ Apple/Facebook/Amazon] have a market value of $3,000 billion, as well as $556 billion in cash and $70 billion in annual investment in research and development. Digital platforms are at the root of the radical transformation of many industrial sectors, from distribution to advertising, but also the way of life of our societies. Several economic concepts, particularly industrial microeconomics, are being challenged. Another issue concerns our legal systems: does the power of platforms require the intervention of national or supranational institutions? The question of regulation can be addressed from both a legal and an economic point of view. As Jean Tirole pointed out in Economics for the Common Good, GAFA illustrate the economic phenomenon of “winner takes all.” The number of users has a direct effect on the development of the platform. It is possible to compare this problem with the notion of natural monopoly. The question arises as to whether a certain form of regulation should apply to platforms, such as sectoral regulation. The other bias is whether our competition law needs to be adapted or whether it is already well equipped. The fundamental criterion for assessing the practices of these platforms in competition law is the subject of an important debate: should the notion of consumer welfare be supplemented by other concepts such as equity? Some regulators seem to want to change the application of competition law in this respect.