Let’s peek behind the curtain. You see a post with 10,000 "free cookies." How did the poster get them?
How to recognize scams and malicious offers Free Netflix Premium Cookies
Sites offer a JSON or Netscape-format cookie string that you can import into your browser using an extension like EditThisCookie Let’s peek behind the curtain
If you use these cookies while logged into your own accounts on other tabs, some malicious scripts on these "cookie-sharing" sites can attempt to hijack your own session data. Extremely Short Lifespan: Free Netflix Premium Cookies