Around 9 p.m. Monday a police car playing a prerecorded message arrived, warning protesters they were in an unlawful assembly and those remaining could be subject to projectiles and chemicals. For the next few hours, a police car would drive up to an entrance and play the message, giving protesters 15 minutes to leave. At first, protesters would rush to the barrier with the car and call on the police to “go home.” As the night progressed and more students trickled out of the quad and recognized the pattern, the response became smaller.