[usr1106]

AWS is a bad service because they don't let the customer set billing limits.

It seems earning money from users' mistakes is part of their business model.

Yes, resource limits are not a silver bullet. Users will complain when their important service goes down because it would have gone slightly over budget during "normal" use. Implementing it in a reasonable way is not perfectly simple. Probably you want separate limits for network, storage, and processing as well as different ways to enforce the limit. Deleting all S3 data might not be what many users would want. They might still be willing to pay for keeping the existing data.

And obviously changing the limit must not be possible with the same credentials that allow you to use resources. Another fundamental challenge.

But with the size of AWS's business there is no excuse not to implement anything. They just value profit over customers.

(Sorry, not a reply to the original poster's question. I don't have anything significantly different from what has been mentioned by others.)