In answering patent infringement complaints, defendants often do their best to throw in any potentially supportable equitable estoppel / implied license defense they can think of. But in patent actions, these defenses can be hard to prove and are rarely successful. They typically drop off at some point later in the case.
This week we got a great example of what a successful equitable estoppel defense looks like, in an opinion from Judge Bataillon granting summary judgment on that basis.
Basically, it involved lots of incredibly strong facts.
The defendant is Sirius …