Part of what I like about the site is that it allows you to organize your notes by class, edit them, as well as share them by tweet or facebook. You can also view your notes with Study Blue's iPad and iPhone apps. One downside, though, is that you can _only_ organize by academic class. I can't create a meta category for a class project or for independent research, just to give you 2 examples. But that's not the biggest problem.
Study Blue is set up to share your notes with other users without asking you. Also, there's no way for you to disable sharing. I know it's not a big deal for class notes, but I'm really glad I noticed before I uploaded anything private. What if a student was working on a project that cannot be shared? Or what if a student uploads a finished assignment? Study Blue could have gotten that student academic suspension.
And in case you were wondering, there's no indication that the site is set up to share everything. I registered twice, and neither time did I have to agree to a T&C nor did I see a mention of whether other people could see my files. I'm a little bothered by this. I know that this is a relatively minor case of piracy, but I still think Study Blue should have asked.
Still, it's an interesting site. Go check it out.