This is an idea that I have been proposing since a while (the first time at the GARR Conference 2018 in Cagliari): "Under this system, every company above a certain size, say, those with more than a ten percent share of the market, that systematically collects and analyzes data would have to let other companies in the same market access a subset of its data. " My argument was that personal data has infinitesimal value to individual users, therefore they are quite willing to relinquish it in exchange for what they consider some useful facility. However large collections of individual data have a huge value: but such a value is a collective one. Hence it should be considered a Commons. As with Commons, they should be not owned by anyone and cared for by a public organization. Who invests in collecting those data should have the possibility to exploit it according to the rules established by the Commons and maintain them available also for others to use on a fair basis. Any entity that reaches a relevant market share should be subject to this provisions. https://www.foreignaffairs.com/articles/world/2018-08-13/big-choice-big-tech