Proliferation of low cost computing is the cause of this, not big players being able to mitigate this. This is not coming from "known botnet IPs", this is from

Proliferation of low cost computing is the cause of this, not big players being able to mitigate this. This is not coming from "known botnet IPs", this is from random infected devices. Some aren't even permanently doing this, just one request from a device per day - it already large enough to cause issues.