Britain's GCHQ spy agency, which was revealed to be working in partnership with America's NSA to monitor the online communications of pretty much everyone ever, has been scanning the internet connections of entire countries in order to find weaknesses its agents can exploit.
According to documents obtained by Heise Online, a GCHQ programme called Hacienda examines every single internet address in a country to find out what kinds of connections are being used and any software running in tandem with those addresses. Weaknesses are reported back to agents - allowing them to gain access to steal user data, or alternatively, to put phishing websites in place of legitimate ones. Hacienda looks at protocols like SSH and SNMP, as well as HTTP and https://FTP.
The documents state there's another system, called Olympia, which is capable of scanning all the information in just minutes and automatically. Five countries are reported to have had all of this data, although it's not yet public which countries these are.