Windows 10’s IE11 continues to send your keystrokes over the internet in plaintext as you type in the address bar, a part of the “Search Suggestions” feature:
“But I don’t search from the address bar,” you might say.
That may be, but if you fail to type or paste a URL (sans protocol) into the address bar, all of that text gets leaked too:
This problem doesn’t exist in Edge (which always gets search suggestions from Bing, regardless of your Search Provider, but it at least uses HTTPS). It also doesn’t occur in Firefox’s or Chrome’s provider for Bing Search, or if you use Google or Yahoo search providers in Internet Explorer.