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Just be careful with all your blocking that you don't cut your nose off to spite your face. I've found that some of my tools don't work on my sites with the entire AWS range blocked, so I went back to just blocking the IP ranges that were hitting my sites. I also don't want to accidentally block real users (I've done that before).
actually if you think you can defend against this you haven't been bombed by anyone good yet. in my case the traffic came from a network of ips and was not a spike on either urls or in total for the day.
I don't think the AWS thing was from Google. Too dicey, if not for publishers than for advertisers.