Previously: https://blog.shodan.io/dont-be-clever/ https://blog.shodan.io/dont-be-clever/ > For example, you might know that Shodan crawls the Internet for ind

Previously: https://blog.shodan.io/dont-be-clever/ https://blog.shodan.io/dont-be-clever/ > For example, you might know that Shodan crawls the Internet for industrial control systems (ICS). One of the most popular protocols in ICS is called Modbus that runs on port 502. At the moment, there are about 17,000 devices listening to Modbus on the default port. It turns out there are also 700 devices listening on port 503, again a one-off sort of situation. Probably over 20k by now