Iron Grip Barbell's US 6,436,015 gets flattened for obviousness
One interesting aspect of the case is that "one of ordinary skill" in this art was found to be a layman, merely an average, ordinary person.
Another interesting aspect is that two competitors of Iron Grip had taken licenses before one (USA) fought back. In terms of the discussion over rational ignorance/optimal ignorance, we see that litigation can resolve bad patents EVEN AFTER some competitors strike deals with patentee, rather than try to invalidate. An interesting question is the position of the early deal making competitors relative to the position of later fighting competitor. Will part of the early deal make them less competitive, or are they better off having licensed early and enjoyed the fruits of another's efforts (under Blonder-Tongue, an invalid patent is invalid as to everyone).
I have been involved in litigations wherein the defendant-client was told of earlier licensing deals to other parties. Problem is, one doesn't know of the details. Different competitors do not always get the same licensing arrangements, and one is generally kept in the dark about other licensing arrangements. Thus, your client, who might want to take a license, has insufficient information to know if he can compete with the other license takers, and litigation might be the preferred course. Moreover, if your client has a patent, falling within the scope of the broader (allegedly invalid) patent, litigation might be very advantageous. If the broader patent is killed off (but the narrower patent of the client is valid), litigation gives the client an advantage over other competitors, even though all competitors (nominally) benefit from the invalidity. One has to study the lay of the land, post-questionable patent.