There are two somewhat sacred places on golf courses -- tee boxes and greens. Drive a cart too close to a green or onto a tee box and you're liable to get berated. Take a chunk out of either on purpose and a marshal or course worker is liable to throw you off the course, perhaps chasing after you with the club you used to leave a mark on the course. It's just not a good idea.
Tiger Woods apparently cares not for this etiquette. Again on Saturday he was unhappy with the way his round was going. And again he took it out on the golf course, throwing clubs and leaving his mark.
So there Woods was on 13th hole, the same place he screamed at himself just a day before. After a bad shot off the tee, Woods didn't just drop his club -- he threw it into the ground, taking a chunk out of the tee box.
It's not uncommon to see divots in tee boxes, sure, but typically they're confined to par threes and holes that require an iron off the tee. On 13, where everyone is hitting driver or 3-wood? It's about as pristine as can be.
This obviously won't go well with everyone picking apart Tiger's body language and chastising him for his outbursts.