T-Mobile joins growing number of sites blocking Firefox in Private Browsing Mode.
When you attempt to log in to the T-Mobile Web site using Firefox in Private Browsing Mode, you’ll now be greeted by this message.
Firefox is no longer supported in private mode
The Firefox browser is no longer supported in private mode on our site. To continue, please take Firefox out of private mode or choose another browser. We recommend Chrome, Safari or Edge.
It turns out that what’s going on is there’s a way to detect Firefox is in Private Browsing Mode and Mozilla is not fixing it. Apparently, a number of news sites, including the New York Times, use this to determine if you’re trying to use the Private Browsing Mode to avoid their paywall, which counts how many articles you’re reading using cookies and local storage, and then demands that you pay to continue reading.
They do it by looking to see if Indexed Database API is available, and if it’s not, blocking your browser.
Fortunately, there’s a Firefox extension called Hide Private Mode that fakes support for this. I tested this (by installing it and giving it permission to work in Private Browsing Mode, of course), and found that T-Mobile is no longer able to detect the Private Browsing session, and allows me to log in.
Mozilla has apparently known about the problem since at least ten years ago, but two years ago, they closed this bug to replace it with another bug that describes the same problem and still isn’t fixed.
Too busy adding “Colorways” that expire on January 16th?
I saw the release notes for Firefox 106, and it’s no wonder people are leaving. There’s been pretty much no work on the browser at all, and in this 6 week release, the only improvements have been an updated PDF reader. There weren’t even any Web Platform changes for developers in those notes.
So much for Mozilla.