Originally Posted by bennos

What you call "opaque" handling is "traditional" web design -- each time you click on a link, you wait a few seconds while your browser talks to a server, the server generates a new page from scratch, the page transfers over the internet, and your browser renders it. Not the fastest of operations.

What Delta is doing is very, very, very, very common, and is how pretty much every modern web site operates. The server delivers the initial page to your web browser. However, when you click on many (but not all) links, your browser only requests a small bit of information from the server (in this case, the json file with all your demographic information), and only re-renders the portion of the page that needs updating. This is much faster and more responsive to the user.

You can see this on the main delta.com page. When you click "My Trips" and you get the spinning thing before your next trip renders, that's what's happening. Compare vs some other link where the entire page refreshes.

Technically, there's nothing "unsafe" happening here, no matter how freaked out people are in seeing their data. Privacy issues (including sharing this data with corporate partners) are another topic.