Who can invite me to a group?
An iGap user can use privacy settings to prevent being added to groups unintentionally.
Just like channels, you should go to setting and select the “Privacy and Security” item. Then click on the “Groups”.
The option “Everybody” makes it possible for any user (contact or non-contact) to add you to any group.
The option “My Contacts” makes it possible for your contacts to add you to any group.
By selecting the option “Nobody” no one can add you to any group.