I've found there are many providers that have completely disconnected autonomous systems. For example Yipes (6517) uses L3 on the west coast and Williams on the east coast. 66.7.129.0/24 is advertised under their AS through WCG and 209.213.209.0/24 is advertised under their AS through L3.
And the number of connected autonomous systems with de-aggregated prefixes appears to be even more common than a disconnected AS. It would seem that many (most?) network operators are just ignoring the more vocal opinions on NANOG. -Ralph
