I noticed them in my DNS logs, trying to do AXFRs of random zones I host. The probes are coming from Hetzner, a low-cost German hosting provider with a history of tolerating dodgy customer behavior.
Their website, which is hosted at Vultr, airly assures us it's nothing personal, they scan everyone to make the Internet better, just filter us, but if you insist, you can send objections to n...@m-d.net. Any idea who they are? I expect it's more likely that they're self-important than evil. but still, sigh. R's, John
