The control centre access from the lock screen takes 2 seconds to turn off
setting>> control centre >>> turn off access in lock screen
As for the finger print scanner, yes you too can do a csi style job
it wasn't jst a photograph of a finger print, they took a high res picture then printed it onto plastic so the ridges were recreated then it was covered in glue which is later peeled off & used on the scanner.
I don't think you need to worry about your m8 doing that down the pub
