As one example, the U.S. Federal Communications Commission uses it in its Broadband Data Collection program. You can see some of how it's been implemented here: https://broadbandmap.fcc.gov/
Edit: It seems some people get a blocked message when visiting the base url. The home path may work better? https://broadbandmap.fcc.gov/home
That's really neat. Here's a screenshot for people who can't access that URL: https://gist.github.com/simonw/eb31ec34af16a1e19ee0d7ca90e8a...