According to a leaked document from German federal office for Information security (BSI). Indicates that Backdoor  are present in windows 8 which could allow the NSA to control the computer.

The TPM chips allows software that what should be run, or not run on the computer, the current version allows users to chose it operate by itself in default or to set it off or manually chose its operation, the problem is with the the new version 2.0 which is always ON and is controlled by the operating system, user cannot modify or interfere in its operation.
German federal agencies are concerned that Microsoft could be compelled in future to hand the TPM 2.0 keys to NSA. which could provide a permanent effective backdoor to all windows 8 users to NSA and could never be closed, nor be monitored to see by whom and when it was used.
The problem does not end here, but it could go to some further serious security risks of being controlled by the country which manufactures the chip. According to researchers the TPM keys could be intercepted by china, who are the manufacturers of the chip.

Theoretically which will allow both NSA and Chinese Authorities to control and handle all the data of windows 8 users, without the user being aware of it.

In a press statement released late Wednesday, the BSI insisted that “From the perspective of the BSI, the use of Windows 8 in combination with a TPM 2.0 is accompanied by a loss of control over the operating system and the hardware used.”