they're wrongly using a normal situation. The internet is especially built so if a path to a destination stops working, an alternative path is chosen. The protocol responsible for managing this is BGP. The time taken by the protocol to chose and switch to an alternative path when the primary one goes down is called "convergence time". That time can be anywhere between microseconds to many minutes long. During convergence, any communication trying to use the old path will get lost, ... of course, it's down!! !!
Do you have any idea of how many of the trillions communication links making the internet goes down throughout the world at any given time ? Yes, many thousands. In fact, BGP is constantly busy, computing new paths... so if you program a bot that will go out there and look for "black holes" (un-completed convergences) you'll find a lot... i mean... A LOT ! !! ! 