In the past, finding the location of the data behind a web map was a huge pain. Now, with Pine, its easy. Simple browse as usual, and the extension will let you know when its found an ArcGIS Rest Server. Click the Pine tree and you'll see a nice list of servers you've discovered, and you can then traverse it.
Just open up a map, and everything is handled for you.
Not only does it discover data for you, it also sends the data it discovered to a central place, where everyone can look at what you discovered, and you can see what everyone else has discovered.
Search at: https://pine.center
Reason for needing access to browsing information:
To detect when an ArcGIS Web map is loaded on the browser, we need access to what urls are being requested by the browser. We never read any content, so we don't know where you're visiting on the map, just that you're visiting a map, and we traverse the various ArcGIS servers for you.