This question here is similar to the same question concerning
telemarketers and wrong numbers.  They think it is rude of us to hang up
on them.  It ain't, folks.  It is impossible to be rude TO rude people.
It is not rude to bounce museum visitors for repeated bad behaviour.  It
is not rude to eject noisy people from theaters.

I haven't ever seen anyone chewed out on this list for one mistake.  I
don't know what private messages might have been sent to the REPEAT
offenders but nothing I have read here qualifies as rude, considering
the gross laziness of those involved.  On top of it all, even if there
is some problem with unsubscribing, sending repeated messages to ALL of
US does no good of course.  It's just plain stupid and jerky.

I have to agree with whoever said it appears that they are TRYING to
irritate us to achieve their ends.

'Peter Youngman