Another use for these defensive patents is renting them out to smaller companies in licensing agreements should a smaller company find itself party to a patent

Another use for these defensive patents is renting them out to smaller companies in licensing agreements should a smaller company find itself party to a patent lawsuit. It's basically impossible to write any software without infringing on some patent, so it's only a matter of time once a company gains some visibility before a competitor tries to put a damper on their growth with a patent suit. Licensing a portfolio of a few thousand patents for a few years lets a smaller company fight back (since the competitor is almost certainly infringing on some of those garbage patents).