The grey market doesn't mean stolen - it just means unauthorized distributors. Companies building a product will end up with excess parts -- either they bought

The grey market doesn't mean stolen - it just means unauthorized distributors. Companies building a product will end up with excess parts -- either they bought too many to satisfy minimum purchases, or changed the design, or cancelled the product. They sell these parts to brokers, who then resell them. The way to avoid this is to limit sole-source suppliers and make sure there are backup plans (parts that fit with same footprint, etc.)