I'm obviously talking about the extension and not the website.
You still didn't show me the license for anything BPIP...and you claim it's open source.
Please show me the license.
.xpi files are Firefox extension files. When you install the BPIP extension, its data is stored in a .xpi file on your computer. We aren't downloading and editing anything, but rather opening the extension's source code to examine it.
You are downloading files the moment you installed extension in your browser.
Why do you think there are licenses for extensions?