[3pt14159]

Fun story about this. I know one of the former guys at Xobni back in the day when it was still a thing. They had made an enterprise version that was sold to companies like Apple, Intel, etc. But even though the enterprise software no longer made external API calls, the company still wanted usage metrics so they could monitor feature usage. Knowing how locked down the networks were at companies like this, they exfiltrated the usage data via infrequent DNS requests to their DNS server. Everything was going fine until one day a dozen or so users at Intel stopped reporting. Hours later all of Intel stopped reported. Within the next day other companies started coming offline. Apple first, then some other large tech company and then a whole slew of them.

Turns out when you spy on your users word gets around.