I am searching for a database detailing post-grant legal events such as licensing of rights or transfer of ownership.
I am willing to subscribe to a payment-based database.
There is no central database that lists licensing rights. Since those are private contracts between parties, there is no obligation to make the knowledge public, and many times it is deliberately confidential. You can search SEC (or foreign equivalent) filings, Press Releases, and markings on a product in a catalog, but it will only be made public if there's a reason to do it. Ownership has a little more clarity because the parties usually, but not always file new assignments. You can find those under "Legal Events" at Espacenet, or at the very end of a Google Patents page. There are more obscure ways at the USPTO to find the assignment reel, but I forget exactly where to go for that.
Date Code Event Description
Aug 16, 2012 AS Assignment
Effective date: 20120813 Owner name: HON HAI PRECISION INDUSTRY CO., LTD., TAIWAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WU, JERRY;REEL/FRAME:028794/0551