Earlier, it was reported that group privacy was created which made it possible to choose who may or may not invite you to the group.
The new group privacy settings option lets you blacklist specific contacts while you accept group invitation from trusted sources.
The Group Privacy Blacklist function replaces a previous option which prevented all users from automatically inviting you to groups with a new setting named “My contacts except…”.
In cases where group invites are blocked, users will be prompted to send you a private invitation through the individual chat, giving you the chance to join the group.