In the best example I've seen of a carrot on a stick since those chocolate bars I got for giving blood, Fortnite fans have noticed a snazzy premium dance you can get for free - if you enable two-factor authentication (2FA) on your Epic account.
Boogie Down is a legendary dance awarded when you sign up your Epic log-in for 2FA via email or an authenticator app.
For the uninitiated, 2FA means you'll get an email or alert if a new device signs in to your account, and then a prompt to enter a security code to ensure it is actually you doing so.
(Also, if you are uninitiated - it's probably a good idea to enable 2FA now.)
As Epic will regularly warn you via Fortnite's loading screens, the game's popularity means there are plenty of scams out there which will try to trick you into giving over your account details in exchange for some bogus V-bucks offer. For better or worse, Epic will never ask for your password - or give you free V-bucks via some dodgy Russian website.
As emotes go, Boogie Down is nothing overly special - it's a dance, with no added props or effects. Still, considering the prices for Fortnite cosmetics usually, securing your account has never been more worthwhile.