> If you use Firefox to upload a file to a website then, legally speaking,the browser is acting as a "publisher"of that file.
If that's the way the law is interpreted, it's silly.
The "publisher" in this case would be the website the file is uploaded to. If the website doesn't make the file public, then they're not a "publisher".
The browser is merely acting as a tool to do the uploading. Firefox shouldn't be held liable for the contents of the file any more than any other web client. If it did, tools like cURL should be liable in the same way.
Somewhere along the way web browser authors forgot that they're merely building a web user _agent_. It's a tool that acts _on behalf of_ the user, in order to help them access the web in a friendly way. It should in no way be aware of the content the user sends and receives, have a say in matters regarding this content, and let alone share that information with 3rd parties. It's an outrageous invasion of privacy to do otherwise.