I've had my cable company call me directly about an account issue and told them I couldn't validate it was them and the person got somewhat irate with my response, insisting there was no one I could call to verify them and that it has to be handled on that call. Turns out it was just a sales call (up selling a product) - which probably speaks to the level of talent they hire for that.
ddos as a service providers (aka booters/stressers) proxy L7 request floods via VPN providers. At some point the VPN providers might actually care to kill off those accounts / better tighten up their free tiers, but they don't care at the moment.
When I worked at an ISP in the 90s the amount of threats and verbal abuse from customers was wild.
One guy who ran a event ticket operation (selling tickets to events) we installed a T1 for the phone company wouldn't go out unless they could bring a security guard. The same guy once came to our office and waited outside in the parking lot and followed one of my coworkers home demanding that she fix his internet. Her father came out and confronted him and he took off.
Another time someone was mad that his address didn't qualify for DSL because "the man was keeping him down from getting fast internet".
Later in life I worked at the phone company and linemen told me stories about being high on a pole in rough neighborhoods and being accosted by folks on the ground brandishing pistols demanding to know whose phone line they were tapping (they tried to explain that stuff is done remotely but they didn't understand).
Didn't someone actually get the configs that showed it was a bgp prefix filter denying accepting the bgp announcement from a customer? Isn't that a far cry from null routing? They're just choosing not to learn it from a customer. And if you buy the "HE is a tier 1" then whatever other peers were announcing the prefix would have been accepted by HE.
