TightWind is written by Kyle Baxter. Stay Hungry. Stay Foolish.

Marco Arment:

If someone threatens your small business with a patent lawsuit, it doesn’t matter whether the patent is valid. Because for you to prove that it’s invalid would take far more time and money than you probably have. The only sensible course of action, the path taken by almost everyone threatened by patent litigation, is to settle with the patent-holder as quickly as possible for whatever amount of money they demand.

In practice, therefore, an issued patent is a valid patent as long as the patent-holder doesn’t try to sue anyone too large. (And even the largest corporations usually settle.)