A few weeks ago I went along to the weekend morning roll up and about 20 of us were standing next to the tee waiting for the groups ahead to clear. One of our party was taking practice swings towards the group (something I hate seeing) and caught the ground, sending dirt and debris into the face of the guy standing next to me. Fortunately he was turned slightly to one side so it hit him in the side of the head rather than in the eyes but it still could have been nasty.
Another time, I saw an out of control motorized trolley smack one of my party square in the nether regions. Admittedly that was quite funny and he was fine after a few minutes but it must have hurt.
So, from the comic to the downright scary, what's the most dangerous behaviour you've seen while on a golf course?