[chipperyman573]

Out of curiosity, why does Amazon consider it their responsibility to prevent that? I'm personally glad that they do, but bots use resources, which is good for Amazon (money in their pocket), and as far as I know Amazon doesn't have anything it wants to protect from bots (at least, anything that would be heavily limited by IP).

[cperciva]

In addition to the answers other people have given about not wanting AWS IP space blacklisted, people who are intending to do use services for nefarious purposes have a nasty habit of paying for them using stolen credit cards.

[bjeanes]

Well, one explanation might be the reputation of their IP ranges. Already, payment processors and some mail servers will give extra scrutiny to IP ranges belonging to AWS. If AWS is made attractive to that audience and damage is done to the reputation (in various systems) of those IP ranges, their offering becomes less compelling to all customer demographics.

[openasocket]

From a rational self-interest standpoint, bots tend to get their IP addresses blocked by whoever they're targeting. Which means the Amazon IP address space gets on threat lists and block lists. The bot owners can just generate new instances with new IP addresses, and then some legitimate customer spins up an instance and gets their address, and wind up on blocked. The bots keep going until various services decide to just block all of Amazon's space, the same way they would for Tor exit nodes or other things associated with shady activity.

[toomuchtodo]

As a good netizen, you want to ensure that other providers don't blackhole your IP blocks (which they will if you allow abuse to be emitted from said IP blocks).