Bengal cats are illegal or restricted in some places primarily because they are hybrids between domestic cats and wild Asian Leopard Cats, which raises legal, health, and environmental concerns. Their status as hybrids means they are sometimes classified as exotic or wild animals rather than domestic pets. This leads to several key reasons for their illegality or restrictions:

• Bengals are descendants of wild Asian Leopard Cats, and some states treat early generations (F1-F4) as wild animals, which are often illegal to keep as pets due to laws against owning wild/exotic animals.
• There is no USDA-approved rabies vaccine for hybrid or exotic animals like Bengals, causing concerns about rabies control and public health in some states.
• Environmental concerns also play a role, since Bengals could potentially threaten local wildlife if they escape or are released.
• Some states, cities, or countries require Bengals to be a certain number of generations removed from the wild ancestor (like F5 or later) and registered with cat associations before they can be legally owned.
• Specific places like New York City, Hawaii, Rhode Island, Maryland, Connecticut, and parts of Alaska have outright bans or strict regulations on Bengal ownership.

In summary, Bengal cats are illegal or restricted mainly because they straddle the line between wild and domestic status, raising safety, health, and environmental concerns that lead to legal controls.