This is the definition I have seen almost everywhere, but I do not like it. Non-practising entities like ARM and patent-owning universities I would never consid

This is the definition I have seen almost everywhere, but I do not like it. Non-practising entities like ARM and patent-owning universities I would never consider trolls just for being an NPE. On the other hand, even practising entities may engage in troll-like activities, asserting a patent beyond its scope to bankrupt a smaller competitor, because legal costs are not usually awarded in the US for such lawsuits (e.g. Nuance vs Zi). It is just that in a lot of cases, if not most, the troll is a non-practising entity.