No mention of any sort of chat encryption either. As with all the Mail.Ru Group's other services (VK, Odnoklassniki) it is widely understood that the russian secret services have essentially unrestricted access to everything happening on them, so be advised
People don't seem to understand what level of access FSB has there. Like literal spying boxes with APIs pulling linked phone numbers and identities to associate with messages all directly controlled by FSB.
Even rms agrees that games do not need to be open source. It's when the program has control over your actual life when freedoms, privacy and security start to matter.