i have some pdf files which i'd like to upload on my association site thus i'd like them not to be able to download it as it may content some slightly sensitive information .
So ok they could ctrl+c but that would reduce the spreading of the information not to have them locally
quoted answer from a similar question, if you' re using Adobe pdf viewer:
You can NOT prevent users from saving ANY TYPE of document from the web - PDF, HTML, JPEG, etc. It's a "feature" of the web.
What you CAN DO is prevent users from being able to use the PDF once it hits their own disk. To do this, you use powerful Digital Rights Management solutions...: