They not only locked arms; they told the police they would "let them go" if they let their friends go.
I don't think police are much into negotiating like that unless hostages' lives are in danger. Honestly, I thought the police were extremely patient and informative before resorting to using the pepper spray.
They warned every single person sitting on the ground. The guy specifically asked each person, "Do you understand that if you do not move we will use physical force?"
And they still sat there?
Yeah. Pepper in the eyes, bitches.