They are also typically used as a &quot;mutually assured destruction&quot;[1] war chest.  For companies that have no intention of filing a patent lawsuit, but need some kind of insurance against that happening to them.<p>You file, buy, acquire, etc, a large enough portfolio of patents such that if another company sues you, your broad portfolio almost assures they are &quot;violating&quot; one of your patents.  Now you have leverage to make the initial lawsuit go away.<p>[1]<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mutual_assured_destruction" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mutual_assured_destruction</a>