I think NetApp may be finding themselves in a bit of a tough spot if they're not careful. As you may know, they have filed a lawsuit against Sun claiming ZFS infringes on their patents.

Jonathan Schwartz, being a reasonable man, got in contact with Dave Hitz of NetApps to discuss how they could settle this dispute. The response? NetApp want Sun to "unfree ZFS" i.e. retract all ZFS code from the free world - barn doors and horses come to mind here, and limit it to only run on computers and not storage devices - aren't storage devices computers too?.

Naturally, Sun declined, but instead fired off it's own reciprocal suit.

To quote Jonathan Schwartz's ZFS Puts Net App Viability at Risk? blog post:

So later this week, we're going to use our defensive portfolio to respond to Network Appliance, filing a comprehensive reciprocal suit. As a part of this suit, we are requesting a permanent injunction to remove all of their filer products from the marketplace, and are examining the original NFS license - on which Network Appliance was started. By opting to litigate vs. innovate, they are disrupting their customers and employees across the world.

In addition to seeking the removal of their products from the marketplace, we will be going after sizable monetary damages. And I am committing that Sun will donate half of those proceeds to the leading institutions promoting free software and patent reform (in specific, The Software Freedom Law Center and the Peer to Patent initiative), and to the legal defense of free software innovators.

Sun are not known for suing for the sake of suing, so I suspect they've got some pretty sound arguments against NetApp.

Good luck NetApp, I think you may have just woken the sleeping rottweiler you really didn't want to nudge, and now he's going to tear a chunk out of you.