Cosa continua a svegliare il mio Mac dal sonno?

Il mio Mac si sveglia costantemente dal sonno per apparentemente senza motivo. A metà della notte, a metà giornata, non riesce proprio a dormire. Perché? Ho eseguito pmset con i seguenti risultati:

[redacted]:~ [redacted]$  pmset -g assertions
2015-01-26 08:27:29 -0800 
Assertion status system-wide:
   BackgroundTask                 0
   ApplePushServiceTask           0
   UserIsActive                   1
   PreventUserIdleDisplaySleep    0
   PreventSystemSleep             0
   ExternalMedia                  1
   PreventUserIdleSystemSleep     0
   NetworkClientActive            0
Listed by owning process:
   pid 72(hidd): [0x0000b0bc000906ce] 18:03:19 UserIsActive named: "com.apple.iohideventsystem.queue.tickle" 
   pid 26(powerd): [0x000000230008012c] 43:45:02 ExternalMedia named: "com.apple.powermanagement.externalmediamounted" 
Kernel Assertions: 0x10c=USB,BT-HID,MAGICWAKE
   id=501  level=255 0x4=USB mod=1/24/15, 12:48 PM description=EHC1 owner=AppleUSBEHCI
   id=503  level=255 0x100=MAGICWAKE mod=1/26/15, 6:47 AM description=en0 owner=en0
   id=504  level=255 0x8=BT-HID mod=12/31/69, 4:00 PM description=com.apple.driver.IOBluetoothHIDDriver owner=BNBTrackpadDevice
   id=506  level=255 0x8=BT-HID mod=12/31/69, 4:00 PM description=com.apple.driver.IOBluetoothHIDDriver owner=AppleBluetoothHIDKeyboard