Most Americans aren’t used to seeing anything that looks like a tank in their neighborhoods. Yet with police departments from California to Texas to Ohio State University acquiring armored vehicles from the federal government, that may soon change.

These armored vehicles, designed to fend off insurgent attacks and capable of withstanding .50-caliber rounds, are impressive pieces of machinery. But they’re also intimidating to civilians and can do a lot of damage to people and their property. Their use should be carefully limited by legislators.

Why are we seeing so many of these armored vehicles in the first place? The Department of Homeland Security began funding armored vehicles in the wake of 9/11 to help localities prevent terrorist attacks. As our involvement in Afghanistan and Iraq winds down, the Department of Defense is donating mine-resistant armored personnel carriers (MRAPs) to local police.

Few doubt the importance of protecting Americans against terrorist attacks, mass shootings, and natural disasters. In such circumstances, armored vehicles could be used to pursue active shooters and rescue injured civilians while minimizing risk to officers and other first responders.

But some are concerned that the costs of introducing these vehicles into domestic law enforcement will outweigh the benefits. Even if they are acquired on the cheap, they will require fuel and maintenance and personnel will have to be trained to operate them. These things are also huge, heavy, and capable of doing a tremendous amount of damage. They could tear up roads and bend bridges.

They’re also scary. The Wall Street Journal reports that when the police department in Salinas, California, acquired an armored vehicle, citizens took to Facebook demanding to know when their town turned into a battlefield.

Finally, there is the possibility of overuse. In 2012, Senator Tom Coburn (R–OK) criticized the procurement of these vehicles by local police departments, pointing to the fact that one jurisdiction cited “protecting the town’s annual pumpkin festival” as a reason for purchasing an armored truck.

What should we do? America’s experience with SWAT teams may be instructive. Major police departments developed SWAT teams in the 1960s to deal with states of emergency that resembled urban warfare—mass riots, hostage situations, etc. Today, as Radley Balko and others have documented, they crack down on poker games, conduct regulatory raids, and swoop down on monks who overstay their visas.

As in the case of SWAT teams, the answer isn’t necessarily to ban MRAPs from all domestic law enforcement. Legislators could draft statutes and ordinances that restrict armored vehicle use to specific emergencies and prevent them from being acquired by police departments in the first instance except in the case of demonstrated need—as opposed to simply because a neighboring jurisdiction has one and they want to look “tough on crime,” too.

Although the sight of a MRAP in one’s neighborhood may be jarring, law enforcement occasionally needs a “bigger boat.” Not everything, however, should be treated like a Great White. In fact, very little should. There are more catfish than hammerheads in the sea. Local police should reserve these war-ready vehicles for situations that actually resemble wartime.