Does this involve uploading your potentially private PDF file? If so, do people really feel comfortable doing that? If so, this reminds me of free internet fax

Does this involve uploading your potentially private PDF file? If so, do people really feel comfortable doing that? If so, this reminds me of free internet fax services where you upload documents you want to fax to their servers, and they make a local call to fax them to their destinations. Most of what I have to fax these days is to doctors and lawyers. Why on earth would I want to upload such sensitive data to some businesses servers where they can do god knows what with it?