Sites like eBay or Craigslist sometimes sell "used" Flash 8 boxes. While the physical disc is legal to own, the product key is a single-user license. Reselling a key violates the EULA. However, if you buy a sealed, never-opened box, that key is legally yours.
Macromedia Flash 8 is a powerful multimedia authoring software that requires a valid product key to activate and use its full features. By understanding the importance of the product key and how to use it, developers and designers can unlock the full potential of Flash 8 and create engaging, interactive content. Macromedia Flash 8 Key
But before you could publish a .swf file, before you could tween a shape or attach ActionScript to a button, you needed one crucial string of characters: the (often referred to as a serial number or product key). Sites like eBay or Craigslist sometimes sell "used"