When you delete a WeChat message, is it really gone? That's what users in China are wondering after dozens of officials were punished -- thanks to chat logs that they thought were erased.

In a social media post, an anti-corruption body in an eastern Chinese city said authorities got hold of deleted WeChat conversations from a Communist Party official suspected of disciplinary violations, according to the South China Morning Post.

Based on those chats, investigators claimed they rounded up more suspects -- many of whom ended up confessing. In total, 63 people were punished.

But the biggest question remains: How did they access those files?

WeChat insists it wipes a message from company servers once it has reached all the recipients. But some has pointed out that China’s cybersecurity law requires internet companies to retain select data for at least six months.

WeChat’s owner, Tencent, says chat histories can only be found on a user’s devices -- not the company’s servers. If true, it would still be theoretically possible to retrieve deleted chats from the phone itself. 

When you delete a file on a smartphone (or any other computer), it often doesn’t get erased right away. The data remains -- but the phone thinks that space is empty, and it will eventually overwrite the “deleted” file with new data. But until then, it’s still possible for an expert with the right tool to find the original data.

The news set off a lively discussion online.

“Does this mean I’ll have to smash my phone if I want to entirely delete [my chat history]?” wrote on user on the microblog platform Weibo, according to the SCMP.

Another summed up the privacy debate this way: “I finally understand why the US bans mobile phones that are made in China.”