Patent Assertion Entities: Two Big Banks Join OIN to Combat Them With patent trolling on the rise, investment bank Barclays and TD Bank Group have put patent assertion entities on notice by taking membership in Open Invention Network. Two major banks, Barclays and TD Bank Group, have joined the fight against patent assertion entities, otherwise known as patent trolls, by joining the Linux-focused patent nonaggression organization Open Invention Network. Patents are considered to be Linux's and open source's greatest intellectual property vulnerability, an issue that primarily affects users because open source software generally comes with no promised or implied patent indemnity. To address this issue, OIN was established by IBM, Novell, Philips, Red Hat and Sony in 2005 to protect Linux during an era when Microsoft was threatening to take action against Linux users for infringing over 200 Microsoft-owned patents it claimed that Linux violated.