A cease-and-desist letter is no laughing matter - unless, apparently, it's been sent by Netflix .
While hugely successful and uber-wealthy organisations tend not to go too much to town with the "hope you're wells" and kisses in the sign-off, Netflix are clearly an entertainment company with a difference.
As one pop-up bar in Chicago recently discovered.
Like millions of others, the folk behind The Upside Down bar are clearly fans of the Netflix-original drama, Stranger Things.
So much so, it was the theme behind their (unauthorised) pop-up bar. Granted, it looks amazing, but sadly there are some intellectual property issues too.
So they received this letter.
It begins chummily enough: "My walkie-talkie is busted so I had to write this note instead. I heard you launched a Stranger Things pop-up bar at your Logan Square location.
"Look, I don't want you to think I'm a total wastoid, and I love how much you guys love the show.
"(Just wait until you see Season 2!) But unless I'm living in the Upside Down, I don't think we did a deal with you for this pop-up.
"You're obviously creative types, so I'm sure you can appreciate that it's important to us to have a say in how our fans encounter the worlds we build."
The lawyer - clearly a Stranger Things enthusiast - sugars the pill by allowing the bar to see it out its run.
"We're not going to go full Dr. Brenner on you, but we ask that you please (1) not extend the pop-up beyond its 6 week run ending in September, and (2) reach out to us for permission if you plan to do something like this again.“
"Let me know as soon as possible that you agree to these requests. We love our fans more than anything, but you should know that the demogorgon is not always as forgiving. So please don't make us call your mom."
Now, THAT is how you write a threatening letter.