Adding NTP servers to public pools in order to find targets for port scanning: https://netpatterns.blogspot.co.uk/2016/01/the-rising-sophistication-of-network.html (crikey!)
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Fedora may be dropping scp (the protocol, not the command) and NTP in future releases: https://www.phoronix.com/scan.php?page=news_item&px=Fedora-Down-With-NTP-SCP