Yes, just example of law system based on precedents.
USA have a lot of such examples. Something like this - in some town human can`t ride a donkey afternoon. Because many years ago (17-18 century) some guy who was riding donkey in this small town afternoon - he did something bad. So precedential law system does consider that is the best way to avoid "some bad deals" is just forbid to do the same scenery action which led to these "bad deals".
Социальные закладки