Censys has some really great data. If you find this kind of thing important or useful, I'd invite you to participate in a project happening right now in the Caddy web server where we're trying to observe the Internet from a server-side perspective (rather than having clients scan servers) to gain insights and understanding as to the health of the Web and its clients. We seek to answer questions like, "What is being advertised in TLS ClientHellos?" and "Which clients fail to adhere to HSTS?" and "Is this surge of traffic possibly a rising global botnet or a DDOS attack?" and "How many HTTPS connections are being intercepted?" (this one builds off work by some of the Censys team) -- with many more (almost 100 questions). This data set will be unique in that it will be collected from many diverse networks rather than a single proprietary/corporate network, and will be made available to the public for research.

I really encourage you to get involved and participate in this project by submitting feedback, especially if you are a researcher or work in this field. We're at the early stages of choosing technologies, but we'll need more voices to refine the ideas and help with the implementation. The more who contribute, the better. More info: https://caddy.community/t/the-caddy-telemetry-project/3224?u...