It's wrong to dispose of other people's belongings.
John who had borrowed Phil's pen and is walking down the street, wearing a backpack when he notices the pen in his pocket.
John wants to remove the pen from his pocket and put it somewhere else.
John puts the pen in his backpack, so he can eventually return it back to his friend later when he gets home.
John takes the pen and tosses is in the garbage because he's afraid it'll leak in his pocket.
John's friend is delighted that John treats his property with respect and care.
John's friend is hurt that John just threw away something he had lent him and loses trust in John.