IF someone "route flapped" the entire North Korean IP space for any amount of time, one of the 10+ organizations who monitor BGP would have noticed and commente

IF someone "route flapped" the entire North Korean IP space for any amount of time, one of the 10+ organizations who monitor BGP would have noticed and commented on that already....... If Russia et al had the ability to covertly do that...why attack Sony....why not big financial institutions or other such high profile targets....