Even if your connection doesn’t have credentials to steal, anyone who can observe your network traffic can snoop on what files you’re downloading, and a MitM at

Even if your connection doesn’t have credentials to steal, anyone who can observe your network traffic can snoop on what files you’re downloading, and a MitM attacker can serve you altered versions of those files. This is especially problematic given that one of the most common remaining use cases for anonymous-FTP-in-browser is downloading software, so there’s a good chance you’re about to execute those potentially-altered files as code. Of course, unencrypted HTTP has the exact same problems – but browsers are trying to deprecate that too, even if they can’t actually remove support anytime soon.