[EN] A simple system
A complex system
The world is a complex system. This means many factors, known or not influence existing phenomenons. In this type of system, we might talk about "unintended consequences" or sequence of events due to unknown factors, factors that are hard to control or unpredictable.
This risk means that precaution is required before acting and that an evaluation of actions taken and their consequences must be frequently made. Indeed, men do not control reality.
A couple examples...
In 1920, the United States made the trade of alcohol illegal and this lead to an increase in profit for criminal organizations.
To increase the safety of passwords a higher complexity is now commonly required, leading many people to writing their passwords on pieces of paper to remember them.
During the great plague epidemy in London, 1665, cats and dogs were thought to be culprits and killed. The rat population carrying the plague thus proliferated.
When trying to sue someone for publishing a private picture online, this can lead to an increased attention from the media and further sharing of the original controversial picture.