Hank and Warren are right on. I have seen several ISPs (one of which has been around a long time) who don't even understand the basics of CIDR routing or why they should aggregate their announcements. This same group are the ones who are not subscribed to this mailing list and don't go to Nanog events, and there are surly a large number of them.
I think one thing the CIDR report glosses over, with its ranking system is the sheer number of ASes which announce extra routes. At least that is what strikes me when I start punching my local peer (not customer) ASes into the cidr-report website, virtually all of them have an aggregation problem and by percentage of junk announcements, the small ASes are often far worse than the big guys.
That being said, perhaps we need some sort of nanog outreach or BGP support community that larger (or clue full) providers can point their less clue full BGP customers towards. The question then becomes, who would maintain such a group and how do we get the large number of currently non-participating ASes involved?
John van Oppen
AS23265 (which yes, is fully aggregated)