Protesters formed 'a human chain' [=they stood next to each other with their arms linked] around the ancient tree to prevent it from being cut down.
In the United States, the President as the commander in chief is at the head of the military 'chain of command'.
I thought he really won the lottery but he was only 'pulling my chain'. [=he was only playing a joke on me]
(..) Something's up with Sadie. Yeah, I don't know what her problem is. Couldn't get her to come inside. We can't leave her out there. She's all right. I got her on a chain. Sadie, hey, be quiet. Thanks for making this work. I know it was a lot to bite off. It's gonna be great, isn't it? (..)2013 The Conjuring