They've _been_ routed like that forever. That's why people have been using them ...

bdonlan on Feb 3, 2010 | parent | context | favorite | on: Pollution in recent IPv4 allocation of 1.0.0.0/8

They've _been_ routed like that forever. That's why people have been using them - because it doesn't do any harm (the data gets dropped at the first BGP-aware router). The issue is we can't _start_ using them now.