NodeBB core doesn't have anything to prevent this. But plugins can be made to prevent multiple accounts from the same IP etc although it can be easily by passed.
King has trademarked the word CANDY (and you're probably infringing)
In a filing with the US trademark office dated February 6, 2013, King.com Limited registered claim to the word ‘candy’ as it pertains to video games and, strangely, clothing. On January 15, 2014 the filing was approved. And now, a mere five days later, reports are coming in from developers that they’re being asked to remove their app (or prove that their game doesn’t infringe upon the trademark).
All in favour of renaming NodeBB to CandyBB?
Just pure madness. Are the dopes responsible for approving such trademarks from another planet?
Even if you did name it, you wouldn't, sadly, be infringing on any copyright as this isn't a video game and/or article of clothing. BUT HOW DID THEY? WHY? CAPS LOCK CONFUSED MODE INITIATED!