Animal Personhood

Regarding the contention that animals should have legal rights:

In the next few months, an animal advocacy group called the Nonhuman Rights Project plans to file a case on behalf of its first animal client. It has already chosen the plaintiff, a captive chimp, on whose behalf it plans to file a writ of habeas corpus and ask a state court judge to grant the chimp’s liberty.

Their goal is to win animals a toehold in the world of legal rights—a strategy that is the culmination of more than two decades of writing and legal work by lawyer Steven Wise and an allied group of attorneys, scientists, and animal activists.

They hope to have an animal declared a “person” in a court of law, breaking down a legal barrier between humans and other species that has stood for millennia.

Maybe someone can tell me what problem is being addressed by giving animals legal rights. The benefit escapes me.