Comment 42 for bug 15179

Firefox should have in its preferences a checkbox to "make files opened from the web read-only" and that box should be ticked by default.
There should also be a way to set the directory where it downloads stuff opened (as oposed to saved) and the default should be /tmp

You can't save a read-only file on openoffice. So people would be forced to use "Save as".

The /tmp warning on gnome save dialog would do the rest of the trick.