 Even though all the persons with ownership rights were losing money with the empty stores, and stores were in great demand, competing interests got in the way of the effective use of that space.Michael Heller says that the rise of the "robber barons" in medieval Germany was the result of the tragedy of the anticommons.Nobles commonly attempted to collect tolls on stretches of the Rhine passing by or through their fiefs, building towers alongside the river and stretching iron chains to prevent boats from carrying cargo up and down the river without paying a fee.