BitLocker, enabled by default in 11, also uploads your encryption keys to Microsoft by default. Those keys have been handed over to authorities as reported by a recent Forbes article (
direct link,
archive). It should not come as a surprise, of course. If your threat level is more than just your drives being stolen and you care about encryption on a Windoze machine, you should use a password (PIN) and be thankful to Microsoft they won't "accidentally" roll out an update that uploads the actual decryption key your password unlocks at some point in the future.