From New York City to Fargo, North Dakota, cities across the United States say they are issuing curfews to keep the peace.
A curfew allows police the ability without any other reason to threaten to arrest or detain crowds of protesters that linger or groups that appear to be a danger to order.
These curfews can be a deterrent to get law-abiding citizens to head home and allow law enforcement to focus their efforts on the unrest, not getting bogged down with simple violations.
But the deadlines aren’t hard and fast — many of them have exceptions for people heading to and from work, reporters, public transportation and even people buying groceries.
Many protesters have routinely disregarded the curfews, and some police departments have actually allowed peaceful demonstrations to continue even after curfew while focusing their attention on violent unrest.
Curfews like these are commonly used in natural disasters like hurricanes, floods and tornadoes to allow police to stop anyone on the streets and prevent stealing or looting.
Some civil rights organizations think hastily issued curfews are unfair and against the First Amendment. The American Civil Liberties Union of Northern California argued that curfews give police too much discretion over whom to arrest, The Associated Press reports.