Sprint violations

One problem we see is European offices/branches of US companies who want
    to use parts of their "company B" for a European connection

As long as people see IPv4 addresses (as currently used, as routing-names -
darn I wish we had a better piece of jargon there) as a purely administrative
thing, some number you get assigned randomly, this makes sense. We have to
make people think of IPv4 addresses as things which say where you are in the
net, things which are higly ordered.

    I think Sprint's approach is rather heavy-handed and probably a toad
    counter-productive in the long run. I would consider it reasonable for
    Sprint to filter their own funny stuff .. for a considerable length of
    time before filtering other people's funny stuff ... Plus stones and
    glasshouses, etc.

Well, I see your point. Also, if everyone filter out subnets outbound, we
wouldn't need inbound filters, anyway, right?

On the other hand, if Sean et al are willing to take the arrows (arrows ->
pioneers, right? :-), good for them; it will provide cover for providers to
tell their own customers "sorry, there's no use sending out your /28; Sprint
will just filter it". It's always easier to tell a paying customer "no" when
you're just relaying someone else's decision, not your own, no?