Unfortunately, PDFCreator no longer seems to support this.
I have just installed 1.9.3 to test it and regardless of wether I select or unselect the "Allow users to select text" option in settings - Adobe Acrobat can still select and copy the text into a Notepad document. This is the same with and without an owner password unfortunately and is also the same with all 3 levels of encryption... disappointing!
FYI, running Acrobat 11 Reader, PDF Creator 1.9.3, Win7 Office 2013 setup for this test.
For trying alternatives - This site lists several options for installing a PDF distiller which will allow you to print a flat PDF, although beware that converting to images as part of building a PDF will increase the file size a lot.