NEW YORK (CBSNewYork) – Mask gatherings are illegal in New York, with the exception of masquerade parties.

WCBS 880’s Alex Silverman With The Story

READ MORE: 16-Year-Old Killed In Double Shooting On Lower East Side, Second Victim In Hospital

It may be an old law – on the books since 1845 – and it may be obscure, but Paul Browne, the NYPD deputy commissioner for public information, says it’s there for a reason.

Police have used the law five times this week at the protests on Wall Street.

“A couple of people put masks on, and then enter a bank, for example, which three of them did. We caught two. One fled. The police are going to stop them,” he told WCBS 880 reporter Alex Silverman.

READ MORE: CDC Issues New COVID-19 Guidance For Holiday Season

The law was originally put on the books in an attempt to stop uprisings by farmers who used disguises to attack police.

“That has become a worldwide phenomenon when you have people that are declaring war on Wall Street and anarchy that they often cover their faces, not only in this country [but] in other countries. So, we always have to be on top of that because obviously these things have a way of spinning out of control,” said Eugene O’Donnell, a professor of political science at John Jay College of Criminal Justice. “It’s a tool, a device that allows police, in situations like the other day, to try to prevent serious breaches of the peace.”

Obviously, the law is not enforced on Halloween.

MORE NEWS: New Video Shows Woman With Red Gas Can Inside Store Before Fire At Brooklyn Yeshiva

Do you think the law is useful or obsolete? Sound off in the comments section below!