“…It was originally developed to model various physical phenomena (see [1] for a short review), but has by now also become an established model for the spreading of activity in networks, for example for the spreading of beliefs [31,40,58,61], behaviour [38,39], or viral marketing [50] in social networks (see also [22]), of contagion in economic networks [7], of failures in physical networks of infrastructure [65] or compute architecture [35,51], of action potentials in neuronal networks (e.g, [6,24,32,33,56,60,62,63], see also [53] for a review), and of infections in populations [31]. Bootstrap percolation has been intensively studied theoretically and experimentally on a multitude of models, including trees [10], lattices [3,9], Erdős-Rényi graphs [48], various geometric graphs [15,37,55], and scale-free networks [8,12,29,36,50]. On geometric scale-free networks there are some experimental results [21], but little is known theoretically.…”