Dave Rand and Paul Vixie, well known Internet software engineers, started keeping a list of IP addresses which had sent out spam or engaged in other objectionable behavior. The list became known as the Real-time Blackhole List (RBL).
Internet software professionals Dave Rand and Paul Vixie began tracking IP addresses associated with sending spam or engaging in objectionable behavior. They created a list, which was later named the Real-time Blackhole List (RBL).