We need to disable downloads/attachments (zipped files) to non-registered members. Searched but could not find a proper solution.
Great software and great community. We are setting up server so it can handle Discourse properly, but for now it is done deal the Discourse will be the platform for our new community.
This is a good idea and sounds like something we might want to support in core as a flag to enable/disable download attachments unless you are a registered member.
I guess clicking the attachments with this flag set would trigger a login prompt?
Would also be safer from a bandwidth perspective, for sure.
In our example we are giving CMS as open source on GitHub, but the actual CMS templates/HTML need forum registration to download. Something to spark new community growth 
I raise a feature similar to this where downloading attachment is used as an criteria in category permission aside create topic, view, etc… Someone replied that download is served by nginx directly now so its not possible.
Anything has changed?
I am not sure how direct download is problem if you replace attachment with login/signup.
I see that zip files are not supported in upload. Is this config setup or something that we will have to modify in order to attach zipped files? We could also hide links for download. Maybe that could be simpler solution for now.
私も同じトピックを開こうとしていました。この機能は素晴らしいアイデアですね。このトピックが作成されてからすでに約6年が経っています。これはすでにデプロイされていますか？ありがとうございます。
「匿名ユーザーからのファイルダウンロードを防止する」というサイト設定を有効にすることで、軽量な保護を実現できます。より重厚で、はるかに複雑なサーバーサイドの保護については、Secure Uploads をご覧ください。