> We believe there is a serious issue relating to the equivalent of 56 “/20” networks, with a corresponding 230k IPv4 addresses. The total value of these is approximately $5M to $6M
> Over the past few days, we have observed 52 networks in the ARIN (North-America) area concurrently burst into life. Until this week, all these networks had been dormant (not routed) for a significant length of time. Even more unusual is that a different autonomous system number (ASN), also previously inactive, has announced each network.
> In 48 cases, these are /20 networks amounting to 4096 IPv4 addresses, and in the remaining 4 cases, they are /19 networks with 8192 addresses.
https://www.spamhaus.org/news/article/802/suspicious-network-resurrections