[cddotdotslash]

It's a bit extreme, but if your service/site is meant to be consumed by physical users (e.g. a B2C type app), you could probably block the entire IP ranges of all the major cloud providers to prevent this kind of behavior. They all publish their CIDRs onlinez, so it wouldn't be difficult.

[Godel_unicode]

Wait until you find out how many people use vpn services whose end points are hosted in a cloud provider. IP address blocking is a fools errand.