Look an obvious first step against this insanity is to at least act proportionately: block
only those IPs that *have* been a source of too large a problem to be dealt in other ways,
do so only for a limited time (it might be an incremental increase, maybe beginning even
with just few hours, up to maybe 6 months), and *use more proportionate measures when they
(still) might be enough*, such as the slow-down or delays that others proposed, and even
those in incremental increases.
And where there's no unwieldy problem, just do nothing (other than reverting the
damage).
Just a few weeks ago I was pondering how bewilderingly "not badly" Wikipedia
works in practice, despite his debatable mantra of allowing immediate modifications from
anonymous persons.
Please don't ruin it, unless you have very good comprehensive alternatives.
Kind regards,
Gabriele