Whose belongings?

During my trip to Chenzhou of Hunan in mainland China,
in the toilet of one restaurant,
I read this funny joke on the wall.

"A couple is going to get divorced,
and they go to the court for the classification of their properties.
The wife claims that the son belongs to her,
as she gave birth to the little boy.

The husband objects to this explanation.
He defends that when people go to the ATM machine for money,
who inserts the card into the machine,
the money belongs to that person!"