SV:Allow some users to download a file and prevent others
What you're trying to do is not technically possible with QVS. But...here's how I would do it:
Disable downloads for all users on the server through the QEMC
Set a .QVW MIME type in your web server. If you are using QVWS, you can set this directly in QEMC >> System >> QlikView Web Servers >> Web. If you are using IIS, you can add it under HTTP headers (a quick google search will show you the exact procedure). In both cases, the MIME type should be application/octet-stream I believe.
Create a "portal" QVW application that your users will have access to. This portal application will actually just be your regular application; for your non-download users, this will be their final destination. The application can open in AJAX or IE Plugin. For your download users, you will include a link in the application to download the QVW. They will start off in the web application, but can then download the QVW if they want.
You can either use the OSUSER() function in QlikView or use section access to set a flag based on user identity. Your text object would be hidden based on the OSUSER function or the section access flag.
Of course, use proper NTFS permissions and Windows security to make sure that users don't simply email the link to each other.