I stopped some kids from stealing a couriers bike and got called a grass 
They were kicking the wooden fence he’d locked it onto but they were like “it’s him in blue. he’s not looking. do it” And I was like “the one in blue haha?” And then banged on the window and got his attention and they ran away but a couple of them stayed and I gave them a big speech about how he’s “trying to work and how’s he meant to pay his rent or buy food if you take his bike??” but they weren’t interested.