From what I understand, AWS at least is pretty good about giving you at least one "get out of jail free" card if things go awry.

Caps are tough though. I can certainly understand a use case that would want a hard circuit breaker that just kills everything it can once it hits a certain threshold. Sort of; you presumably don't want everything on S3, for example, to be deleted.

On the other hand, moving up the scale of serious businesses, I can imagine it would be hard to specify circuit breakers (rather than just alerts) and you get into issues of terminating services that affect all sorts of other services across the entire account.