A French gendarme holds a Taser in Bordeaux, France, March 7, 2016. REUTERS/Regis Duvignau

The Supreme Court on Monday suggested the Second Amendment, which protects gun ownership in America, should be extended to stun guns. The ruling gives a boost to Arizona-based Taser International, which makes the eponymous Taser used by police departments across the country.

In a unanimous opinion, the justices wiped a Massachusetts court ruling that upheld the conviction of Jamie Caetano, a homeless woman who was arrested and convicted in Massachusetts for carrying a stun gun. Caetano kept a stun gun for self-defense against an abusive ex-boyfriend. Caetano’s lawyers challenged the conviction, saying that Caetano’s use of a stun gun should be protected by the Second Amendment.

The Supreme Court agreed, and suggested that stun guns, which are banned in a handful of states and cities, should be protected as self-defense under the Constitution. It said the Massachusetts court was wrong when it ruled that Second Amendment protection applies only to weapons in common use at the time the U.S. was founded.

However, the decision does not explicitly rule that carrying a stun gun is now legal in every state. Rather, the Supreme Court sent the case back to the Massachusetts court, which will re-examine the case.

Justice Samuel Alito wrote a 10-page brief to support this decision. Justice Clarence Thomas supported Alito's concurrence.

“Courts should not be in the business of demanding that citizens use more force for self-defense than they are comfortable wielding,” Alito wrote.

Caetano’s case, examined recently by International Business Times, reveals a strange irony in America: Because of a strong gun lobby, in some states, it is far easier to obtain a handgun or assault rifle than it is to obtain a Taser or stun gun.

Why? According to legal experts, many local jurisdictions have criminalized the possession of stun guns because they fear their misuse by criminals. But stun gun manufacturers don’t have a significant lobby, compared to the National Rifle Association, which spent $28 million in pro-gun campaigns and lobbying in 2014.

“You try to regulate guns, and the NRA gets upset,” Eugene Volokh, a law professor at the University of California, Los Angeles, told IBT. “Whereas, you try to regulate [stun guns], there’s nobody to speak up for them. ... Nobody has fond memories of going out and stun-gunning deer with their grandfather in the woods.”

Right now, five states — Massachusetts, New Jersey, New York, Rhode Island and Hawaii — and the District of Columbia have bans on the ownership of stun guns for those not in law enforcement. Even some gun-friendly cities, like New Orleans, make it illegal to own a stun gun or a Taser, which is the largest manufacturer of the device.

Today’s ruling does not invalidate state or local bans against Tasers or other electrical stun gun weapons. But it does provide the legal groundwork to potentially challenge these local ordinances.

“The Commonwealth of Massachusetts was either unable or unwilling to do what was necessary to protect Jaime Caetano, so she was forced to protect herself,” Alito wrote. “To make matters worse, the Commonwealth chose to deploy its prosecutorial resources to prosecute and convict her of a criminal offense for arming herself with a nonlethal weapon that may well have saved her life.”