The internet works by organisations "announcing" the IP ranges they're allocated to other networks (ISPs, other large companies etc.) Networks that receive an

The internet works by organisations "announcing" the IP ranges they're allocated to other networks (ISPs, other large companies etc.) Networks that receive an announcement will route traffic for those IP ranges to the network that announced them. The protocol by which this is done is called BGP. The original version of this was created in 1989 and back then everyone involved trusted each other. So there is no security built in to prevent a rogue company announcing addresses they don't own, and therefore pulling in traffic people send to those addresses. Organisations can and do put filters in place to try and stop this, but because it's not a core baked in feature of BGP not everyone does, and issues can happen. Sometimes these things are just mistakes engineers make, re-announcing routes they've learnt elsewhere. Sometimes they are deliberate hi-jacks.