This has little or nothing to do with any "spam" policy.
If a site completely blocks email traffic from another site, and that
site many hours (over a day) after being reliably informed of this and
asked to stop continues to send thousands of messages all falling into
a rathole, then that is not spam, that is software out of control, an
operational problem. To deduce otherwise simply because the source is
a known spammer is pure mind-reading as to intent.
How can a person claim they are merely exercising some right as a
"spammer" when ALL THEIR MAIL IS BEING TOSSED ON THE FLOOR WITH
ERRORS? That's not spamming, any more than hitting yourself on the
head with a bat is baseball.
Sprint can certainly, if they cared, verify that thousands of messages
were being bounced unconditionally yet the other site continued
running one or more software loops sending messages.
To me this is not much different than creating a broadcast storm etc.,
someone is asleep at the wheel or malicious, to the point that it
justified intervention by a vendor as a purely operational problem, no
matter what the "rea mens" (legal term for "state of mind" or
"motivation") of the source of the problem is.
As a culture we're getting way too sucked into this "oh woe there's
nothing we can do" mentality, to the point of acting completely
impotent even in the face of actually rather easy to fix
problems. These spammers have created a state of panic and confusion
in some people, listen to yourselves!
Look, if someone sends packets at you at a fairly high rate,
regardless of the contents, and you have asked it be stopped at the
source, and they don't, and you have gone so far as to block its very
purpose and return an error msg on each and every logical transaction
attempt, and yet they still come, THAT IS AN OPERATIONAL/TECHNICAL
PROBLEM and justifies third-party intervention.
Let's stop being so damned morally confused. One message in my mailbox
is spam, thousands of messages being refused for 48+ hours, non-stop,
is an operational/technical incident, no one is seeing or cares about
the content, it's just an out of control software process which needs
to be treated as such, and stopped.