That’s the title used by Bruce Schneier in a post that draws an analogy of the ways we use our data to a feudal society.
My very short description is that our system of allowing Apple or Google or Microsoft to store our data on their servers and provide hardware platforms with reduced opportunity to manage our own security is a change from the previous model of having our own servers and maintaining our own security and backup.
That is similar to a feudal society in which the peasants work for a lord who provides all their security.