I don't remember where I heard this, but it was recently: the story is that someone created some serious fright with an old prank that involves some chemistry. Baking soda had been poured into ketchup bottles, and when the bottles were refilled and capped, the vinegar reacted with the soda and created pressure inside. The next person who opened the bottle was startled when the pressure blew the cap and contents out of the bottle.
The story is that this caused an actual bomb scare. I'm dubious, and I can't back up my story because I don't remember where I heard it and I can't find anything on Google.
There you go. I'm not suggesting anybody do this. But maybe I'm suggesting we should all be cautious when we're getting into the ketchup bottle at our favorite family restaurant.