I think JohnE is wrong, its not the spot and most spot owners are not the problem ether. Most spot owners understand the spot and its uses, in the same way as most plb users do.

The problem here is the that the spot was hired out to people that don't understand its purpose. And, it was probably rented with no or little instruction. Possibly something like "if you have a problem press this button and someone will come and see whats wrong".

This will always be a problem for kit that is rented out. maybe the solution is to issued a citation for creating a hazardous condition or fine both parties. That way the people renting the machine understand that they have a duty to make sure that they fully explain it use.