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]
(..) Hello? Guys? Will the guards please lock the cage doors at this time? Hey listen! This is some kind of mistake. I didn't sign up for a cage match! Unlock the thing! Take the chain off! Hey, freak show! You're going nowhere. I got you for three minutes. Three minutes of playtime. (..)2002 Spider-Man