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]
(..) - How are they gonna do that? - The train. The monorail follows the water mains to the central hub beneath Wayne Tower. If the machine gets to the station... ...it'll cause a chain reaction that'll vaporize the city's water supply. Covering Gotham in this poison. I'm gonna stop him from loading (..)2005 Batman Begins