Z-Map

[xoxoxoBruce]

Those damn Michigan busybodies are probing your port. A program called Z-Map created by three dudes from the University of Michigan, two PhD candidates, and an assistant professor named Halderman. Halderman? Danger Danger

What the program can do is scan the internet in less than an hour to see who's on and who isn't. They used it to map the Northeast during Superstorm Sandy...

...which shows locations where the number of web servers running the SSL encryption software declined by 30 percent or more, which turns out to be a good proxy for heavy storm damage.

I'll let you geeks figure out what's going on there.
You can get the program here, but they caution...

While ZMap is a powerful tool for researchers, please keep in mind that by running ZMap, you are potentially scanning the ENTIRE IPv4 address space and some users may not appreciate your scanning. We encourage ZMap users to respect requests to stop scanning and to exclude these networks from ongoing scanning.

You know, that old great power, great responsibility, schtick. Of course if you figure out a way to make money with it, especially if you're screwing people over, then you're automatically exempt from that note.