Elon Musk, the owner of X (formerly Twitter), has renewed his criticism of WhatsApp over its handling of personal data. The Tesla and SpaceX CEO questioned the platform's security practices in response to a user query on Saturday.

A user on X had asked, "If WhatsApp messages are end-to-end encrypted, why do we see ads related to the things we discussed in our chats?" Musk briefly replied by saying, "WhatsApp is not secure at all."

This recent comment is part of a broader dispute between Musk and WhatsApp, which is owned by Mark Zuckerberg's conglomerate Meta.

In May, Musk responded to a post on X alleging that "WhatsApp exports user data nightly, which is analyzed and used for targeted advertising, making users the product, not the customer."

Musk supported this claim, saying, "WhatsApp exports your user data every night. Some people still think it is secure," highlighting ongoing concerns about data sharing between WhatsApp and Facebook.

Whatsapp: 'We take security seriously'

Will Cathcart, head of WhatsApp, responded to Musk's claims, stating on X: "Many have said this already, but worth repeating: this is not correct. We take security seriously and that's why we end-to-end encrypt your messages. They don't get sent to us every night or exported to us."

However, security researcher Tommy Mysk weighed in, clarifying that while messages on WhatsApp are end-to-end encrypted, other forms of user data are not. "The metadata such as user location, which contacts the user is communicating with, the patterns of when the user is online, etc. This metadata according to your privacy policy is indeed used for targeted ads across Meta services," Mysk explained. "So, Elon Musk is right," he concluded.

The debate over WhatsApp's data practices is not new. In 2022, during his acquisition of Twitter, Musk argued that Zuckerberg had excessive control over social media, dubbing him "Mark Zuckerberg XIV" in reference to the autocratic French monarch Louis XIV.

The rivalry between Musk and Zuckerberg escalated further in 2023 when Meta launched Threads, a platform designed for real-time online conversations, seen as a direct competitor to Twitter. Despite garnering 100 million users shortly after launch, Threads' popularity quickly waned, but the tension between the two tech moguls remained.