I've done this and I'm sure you have, too. I've also been on the receiving end of this and I'm sure you have, too.

Flashing those high beams to warn other drivers about a police officer ahead looking for speeders is one thing most of us do and appreciate.

Granted those flashing lights often have us double-checking to make sure our own headlights are on, it's common knowledge that it means to slow down, stay alert, and be cautious because something is going on up ahead.

That something is often a police officer with his radar gun.

READ ONWhy Police Ask These 4 Questions After Pulling You Over

So is it illegal if we're caught warning another driver by flashing our bright lights quickly a few times? Is it technically obstruction of justice?

Yes, for decades this was illegal in states or various counties around the country.

Police Radar
Getty Images/iStockphoto
loading...

According to KTLA, this all changed in 2014. So even if this law is still on the books somewhere as obstruction of justice it shouldn't hold if you decide to fight it.

A federal court in St. Louis, Missouri ruled that it's our First Amendment right as drivers in the United States to flash our lights to warn other motorists about a speed trap. Even the American Civil Liberties Union (ACLU) has stepped in around the country to represent people.

READ ON: 3 Reasons Why Police Touch Your Car During a Traffic Stop

This national ruling came from a Missouri case when a driver received a citation after he was caught flashing his lights to notify motorists about a cop radaring traffic according and the ACLU has drivers' backs.

The police cannot retaliate against drivers who have done nothing wrong and are simply exercising their right to communicate with other drivers.

There's also a little-known 1974 United States Supreme Court ruling in Spence v. Washington as well dealing with non-verbal free speech as well.

LOOK: This is the best place to live in every state

Stacker compiled a list of the best places to live in every state using Niche's 2023 rankings, from planned communities to college towns.  

Gallery Credit: Stacker

LOOK: Iconic TV Shows With Only One Cast Member Surviving

From Diff'rent Strokes to Gilligan's Island, several of the most iconic TV shows in history now have only one surviving main cast member. Keep scrolling to see who remains from these beloved programs.

Gallery Credit: Stephen Lenz