We've talked before about how asserting invalidity based on system prior art (as opposed to written publications, for example) can be tricky, because accused infringers can face all kinds of sometimes-unexpected difficulties with proving up the prior art.
Parties often get into sticky evidentiary questions about exactly what kinds of evidence are sufficient to show that the relevant prior art was on sale before the priority date, and how the prior art functioned—and whether that all of that evidence has authenticity or hearsay issues.
On Friday, Magistrate Judge Burke issued a long oral report and recommendation to grant summary judgment of no invalidity based on a system prior art reference. In the case, the defendants relied …
