Microsoft has been criticized by privacy advocates in regards to the data hunger of its Windows 10 operating system. The operating system slurps data like there is no tomorrow, especially when systems are set up using the express settings.
Experienced users may disable telemetry and data collection partially during setup, and then some more afterwards using the Registry or Group Policy.
What makes this problematic however is the fact that it is nearly impossible to stop all of the data collecting that is taking place.
While users may disable some, for instance by using privacy tools (of which there are plenty), others cannot be disabled or stopped that easily, for instance because of hardcoded host and IP address information that bypass the Hosts file of the operating system.