↑Steven ↑Levy, author of ‘↑Hackers: Heroes of the Computer Revolution‘ (1984), among others, has written a comprehensive article, published at Wired, on the complex of problems comprising patents, the patent wars, and patent trolls. Along a suspenseful storyline, and by using some fine metaphors from the cold war and beyond, he makes the matter perfectly clear and understandable.

That’s traditionally been the spirit in which large companies have built their patent stockpiles, as a purely defensive measure. They were dissuaded from suing one another because they knew their target likely had patents that covered similar territory and they could be countersued quickly—the legal equivalent of mutually assured destruction. […]

That labyrinthine process, combined with the intricacies of the court system, have made trolls more powerful than ever. NPEs [nonpracticing entities—companies which neither manufacture anything nor offer any services but solely make profits from their patent portfolios the lawyers’ way] have nothing to lose. Because they don’t create anything, they can’t infringe on anyone else’s patents, no matter how overblown. That means they can’t be countersued. This isn’t mutually assured destruction; it’s asymmetric warfare.