Full Self-Driving, or FSD, is one of the most controversial parts of Elon Musk’s Tesla strategy, with regulators calling the branding misleading and dangerous. But love it or hate it, Tesla has unleashed FSD, with a free trial for millions of U.S. drivers. That means more data -- an essential component to any company trying to develop autonomous driving. Tesla's approach to gathering all that data could prove all of Musk’s naysayers wrong, or leave it continuing to play catch up with more advanced self-driving tech. This week on TechCheck, Tesla’s big FSD gamble.