An interesting thing occurred just now. I wandered onto a Flash-based website and when I was about to start browsing, Mac OS X displayed a warning telling me that the application (Adobe Flash) was trying to access a specific font in my system. I'm conflicted. In terms of security, this feature is great. Yet in terms of usability, I think this is horrible.
This is the hypocrite in me speaking. I absolutely love the security features that Mac OS X has and have no reservations in tending to a few additional burdens provided that they are required. However, if I were a Flash developers with the intention of building an online Flash application, it would be upsetting to know that a portion of my audience base would get a security warning concerning them about a particular font.