I deleted all messages from all devices, including iPhone, iPad and Mac. There are zero messages right now. I deleted Messages folder in Library and let Messages generate new one, just to be sure that they are removed from hard drive. I've deleted all backups that were kept in iCloud for each device separately and created new backups with all messages erased. However, there's still 26.6GB of messages in iCloud that I cannot delete?! I've read all over the internet about this topic and just couldn't find a solution. Messages are one of the most private things we have, and I just can't imagine there's no way to be deleted from iCloud? Please check my screenshot taken from System Preferences > iCloud > Manage Storage.