The reason why bottled water was banned in the prisons

In the old days, the accused was interviewed at Anyang Prison
Pay back with a bottle of bottled water while going:
But the guards,
‘When Kwang Seok -young comes here, the poet Ko Eun
There was a drink of soju in the bottled water bottle.
It is prohibited “
‘Is it going to go? “
“No, read the experience later, read the egg ahead of the egg”