Google seems to index links to WhatsApp group invites that may be private, meaning anyone can discover and join hundreds of thousands of WhatsApp groups.

"Your WhatsApp groups may not be as secure as you think they are," Jordan Wildon, a multimedia journalist for German outlet Deutsche Welle, tweeted on Friday. Using particular Google searches, people can discover links to the chats, Wildon explained.

App reverse-engineer Jane Wong added in a tweet that Google has around 470,000 results for a simple search of "chat.whatsapp.com," part of the URL that makes up invites to WhatsApp groups.

Motherboard used a number of specific Google searches to find invite links to WhatsApp groups. Some of the groups appear to not be overly sensitive or for a particular audience. Many of the links on Google lead to groups for sharing porn.

But others appear to be catered to specific groups. Motherboard entered one WhatsApp group chat that described itself as being for NGOs accredited by the United Nations. After joining, Motherboard was able to see a list of all 48 participants and their phone numbers.

Google did not respond to a request for comment.

A WhatsApp spokesperson said in a statement, "Group admins in WhatsApp groups are able to invite any WhatsApp user to join that group by sharing a link that they have generated. Like all content that is shared in searchable, public channels, invite links that are posted publicly on the internet can be found by other WhatsApp users. Links that users wish to share privately with people they know and trust should not be posted on a publicly accessible website."