Except many of the big upstream providers don't actually filter anything. HE.net for example, doesn't. We forgot to create some IRR entries and GTT just accept

Except many of the big upstream providers don't actually filter anything. HE.net for example, doesn't. We forgot to create some IRR entries and GTT just accepted our prefixes. There is essentially no security, it's fairly trivial to hijack whatever space you want. (Doing it undetected is more difficult though!)