This sign I spotted on a small rural road near Mäntyharju, Finland. It is a self-made speed limit sign that states that the speed limit on this road is now 40 km/h. (The actual limit on this road would have been 60 km/h.)
Comparing it to the official signage, the font is clearly not the standard one; see e.g. the following image from the Finnish Transport Infrastructure Agency.
Thus it is obvious to anyone seeing the sign that this is not an official sign, but rather something self made with a purpose of lowering the driving speed. Perhaps the sign poster has wanted to the twisty road more safer, and thus the sign is signaling a dangerous road ahead?
What caught my attention were two things. The first on is that a sign that aims to give commands or limit peoples behaviour also signals that the sign poster claims authority to edict such commands. By erecting this sign and emulating official government signage the sign poster is thus trying to borrow the authority of the government while (presumably) lacking similar means of enforcement. Not unlike animals pretending to be other, more scary animals?
The other thing that caught my attention was that I was driving past this sign with a car that has an automatic speed sign detection system. And this sign failed to register. So the car refuses to acknowledge the authority of this self made sign.