For indentured workers and human-rights advocates across the globe, January 1 was a happy new year, indeed. That’s when a groundbreaking anti-slavery retail and manufacturing law went into effect in California. Although several states already prohibit forced labor and trafficking, the new California Transparency in Supply Chains Act is the first legislation to address the supply chain on an international scale. Its gist: Any Golden State company worth at least $100 million in sales—that includes businesses like Gap and Apple—must disclose on a “conspicuous and easily understood link” on its website if it’s taking measures to eradicate slavery and human trafficking in its supply chain. For businesses that don’t have websites, the disclosures must be provided in writing within 30 days of receiving a written request.