writes with this excerpt from Heise: Since the early days of TCP, port scanning has been used by computer saboteurs to locate vulnerable systems. In a new set of top secret documents seen by Heise, it is revealed that in 2009, the British spy agency GCHQ made port scans a "standard tool" to be applied against entire nations. Twenty-seven countries are listed as targets of the HACIENDA program in the presentation, which comes with a promotional offer: readers desiring to do reconnaissance against another country need simply send an e-mail.
Also from the article:
The list of targeted services includes ubiquitous public services such as HTTP and FTP, as well as common administrative protocols such as SSH (Secure SHell protocol – used for remote access to systems) and SNMP (Simple Network Management Protocol – used for network administration) (Figure 4). Given that in the meantime, port scanning tools like Zmap have been developed which allow anyone to do comprehensive scans, it is not the technology used that is shocking, but rather the gargantuan scale and pervasiveness of the operation.