This involves the UK. I went to the park with my grandson and his friend to play football. We had quite an expensive, high quality size 4 football. After playing around for a while we went to the park café for a drink and something to eat. Carelessly we left without the football, so I returned there later in the day to see if they had it. The person in charge told me that it had been noticed, but had been put somewhere - he didn't know where. After a brief search he said I would have to go back the following day when his colleague would know where it was.
When I returned the next day I was met by the same individual I had seen previously. He told me rather tersely that he had last seen the ball when some kids were kicking it around, and he had no idea where it was, and it was probably taken by someone. When I expressed surprise that, knowing it was ours, he hadn't taken care of it, he got very defensive and kept repeating himself saying we should not have left it behind - a truism, if ever there was one!
My own contention is that the café has been an accessory to theft.
The café has now installed notices which state that they cannot be responsible for people's lost property. However these were not there when the ball was left behind.