STORY: Meta Platform’s new social media app Threads – the first serious rival to Elon Musk’s Twitter – has already hit a milestone.Meta CEO Mark Zuckerberg on Monday said Threads has notched more than 100 million sign-ups in just five days – dethroning ChatGPT as the fastest online platform to reach that benchmark number.Threads has been setting new records for user additions since its launch last week, with celebrities such as Jennifer Lopez and Kim Kardashian joining the platform.The new app, which pitches itself as the "friendly" option for public discourse online, shares some resemblance to Twitter.It allows posts that are up to 500 characters long and includes links, photos and videos of up to 5 minutes.But it does not yet have a direct messaging function or a desktop version that some users, such as businesses, rely on. Twitter has responded by threatening to sue Meta over the app, alleging that it used Twitter’s trade secrets and other confidential information.But legal experts say that claim could be hard to prove.And the turmoil at Twitter - including Musk’s recently imposed limits on the number on tweets users can see - could potentially help Threads gain more users and advertisers.Still, with nearly 240 million monetizable daily active users, Twitter likely won’t bow to its new challenger any time soon.Threads is currently ad free, and Zuckerberg has said Meta would only think about monetization once there was a clear path to 1 billion users.