In all proposals, webfonts security relies on the integrity of browsers, the integrity of operating systems, some part of the process being kept secret, or best of all, the integrity of users. The first two can and will be hacked with relative ease. Flip a bit, find free font. Webfonts are things that primarily need to create bitmap images on screens across the world. Most usage will be on screen.
Print is another issue that can be solved seperately already.
Let's get the screen right before giving away the fonts. Already sites are beginning to provide fonts to their viewers. These fonts are scalable, but won't provide good results in all resolutions, neither do they print well. Yet people like it enough to maintain the supply. A webfonts system that provides the possibility to deliver appropriate pixelfonts to the client, without enabling access to outlines is the best solution for the time being.