Ransomware typically doesn't work in that way. It's typically used to target, and then it's holding something for hostage, whether it's holding your data for hostage by taking it out of your system and then using that to say that if you don't pay them they're going to release the information, or by encrypting your data and making it unavailable to you. It tends to be done on an organization-by-organization basis.
In terms of a mass ransomware type of thing, we have seen where ransomware will propagate. We saw some examples where it impacted a company, such as Maersk shipping, for example, which was impacted by ransomware, and the National Health Service in the U.K., where ransomware started to propagate and get out of control.
The defence against this is really that you start to block the infected systems and start to do a containment model. At the same time, you start to share the information and innoculate. There are responses in place, and there are things that can be done to protect against it. The worldwide community is pretty adept at dealing with it, but that doesn't mean that there aren't victims of consequence during that process.