Law evolves over decades or centuries. Computer related patents are very new to the scene (in law years). They are getting better but there are still some clunkers out there.
In other more mature industries like medical devices, autos (auto parts really), kitchen gadgets, fasteners, packaging, HVAC, etc., the patent litigation (including trolls) is fierce too and has been for decades.
Law evolves over decades or centuries. Computer related patents are very new to the scene (in law years). They are getting better but there are still some clunkers out there.
In other more mature industries like medical devices, autos (auto parts really), kitchen gadgets, fasteners, packaging, HVAC, etc., the patent litigation (including trolls) is fierce too and has been for decades.