The picture above is a screen capture from the Fox 2002/2003 show Firefly, depicting the character Jayne Cobb (Adam Baldwin) in a hat made for him by his mother. The hat has become known as the Jayne hat and is a popular piece of memorabilia among Firefly fans. But in replicating the Jayne hat, some Firefly devotees have run into the legal limitations entailed in using someone else's designs and patterns. To wit: that while you can knit anything you like for personal use, selling reproductions of other people's work is another matter. Fox, which is protecting their copyright by preventing unlicensed sales of the hat by Etsy vendors, is on its part experiencing the consequences of getting into a David and Goliath-style legal rumble, those being that Goliath always gets the bad press. No one ever takes Goliath's side no matter how objectively right he may have been, because there's such a power imbalance that the fight automatically seems unfair and because David is the more appealing opponent with the better back story.
While Fox is absolutely legally entitled to stop Etsy vendors from selling handmade Jayne hats in order to reserve the profits of Jayne hat sales for itself, doing so is going to make them look like bullies and alienate the Firefly fan base, which will probably now generally refuse to buy the licensed Jayne hats out of pique. Fox would have been better advised to stick to stamping out any sales of mass-manufactured hats (if any) and to leave the hand-knitting producers alone, knowing their scale of production and market share is guaranteed to be too small to make it worth even the legal costs of sending out cease and desist letters, let alone the risk of offending Firefly followers. I mean, is it really a good idea to mess with a community so fanatical that they're buying and wearing silly hats to reference a show that was only on the air for a few months over ten years ago? Talk about poking the bear.
As any knitter could have told Fox, when considering legal action that old crafting axiom applies: the realization that you can make a certain item (such as, say, granny square pajamas), should not necessarily be followed by the resolution that you should.