Much to my surprise, I managed to snap the pocket clip on my SOG Vulcan Tanto cleanly in half by getting out of my car last week. The clip hung up on the door frame and failed with a loud "PING". The clip has a number of holes machined in it, presumably to reduce weight, but mostly to make it look cool. From my perspective, I've been carrying a knife clipped to that pocket most days pretty much since they started putting clips on knives, and never broken one before.
Fortunately, SOP has a dedicated page to request new pocket clips, free of charge. The page is located here:
Unfortunately, these pretty clips apparently break so often that SOG had to set up a dedicated page to request new pocket clips, free of charge.