Chief Justice John Roberts on Tuesday denied a stay request, though Supreme Court Justice Sonia Sotomayor is looking at one more request, according to ABC News’ Devin Dwyer. As of midnight, they became illegal to own

Though the Supreme Court was mulling an emergency stay requested by several gun ownership advocacy groups, President Donald Trump ’s ban on what he previously called “ devices that turn legal weapons into machine guns ” is set in stone, for now.

Bump stocks ― devices that allow semi-automatic guns to mimic fully automatic fire by shooting many rounds every second ― were banned Tuesday, and efforts to delay the ban have so far been curtailed.

BREAKING: Chief Justice John Roberts has denied an emergency request by gun owners to temporarily stay the Trump administration's ban on bump stocks which took effect at midnight. One more stay request is still pending with Justice Sotomayor. #SCOTUS

In December 2018, the Justice Department ruled in favor of the bump stock ban, which makes the possession of such a device a felony. Trump worked with former Attorney General Jeff Sessions to ban them after the shooting at Marjory Stoneman Douglas High School in Parkland, Florida, which left 17 people dead.

Gun advocacy groups have been pushing back on the ban ever since. Gun Owners of America, its foundation and the Virginia Citizens Defense League requested that the Supreme Court stay the ban while it looked at appeals, alleging that the Trump administration “created a new crime” and violated the separation of governing powers, according to ABC News.

Now that the ban is in effect, some 500,000 Americans who purchased bump stocks will be required to either turn them into authorities or destroy them, ABC reported.

Though bump stocks weren’t used in the attack on Marjory Stoneman Douglas High, they were attached to at least 12 of the rifles found in the hotel room of the gunman who killed 59 people in the Las Vegas in 2017. Using those devices, the gunman was able to fire off 90 rounds in just 10 seconds, and more than 1,100 in total during the attack, The New York Times reported at the time.