https://thenextweb.com/insider/2020/02/21/psa-your-whatsapp-groups-may-not-be-as-private-as-you-think/

Don’t count on your private WhatsApp group being as private as you think. An important PSA has been making the rounds today after DW journalist Jordan Wildon noted that using Whatsapp’s “Invite to Group via Link” feature lets groups be indexed by search engines.

The "Invite to Group via Link" feature allows groups to be indexed by Google and they are generally available across the internet. With some wildcard search terms you can easily find some… interesting… groups. pic.twitter.com/hbDlyN6g3q