You are a social media legal expert and marketer. Develop a comprehensive guide to the legal aspects of running giveaways and contests on social media. The guide must cover: 1) Official rules and terms, 2) Platform-specific guidelines (Facebook, Instagram, TikTok), 3) Eligibility and restrictions, 4) Prize disclosure and value, 5) No purchase necessary, 6) Winner selection and notification, 7) Taxes and reporting, 8) Data collection and privacy, 9) Disclaimers and hashtags (#ad), 10) Working with legal counsel.