I have seen many friends having interesting notes or even important details about their projects in Facebook. It should always be kept in mind, Facebook is not a safe place to store the important materials at all. There may be some security issues in Facebook. But here I am not talking about them. The problem I see with Facebook is their policy of banning accounts.
Being a super active user is more than enough for an account to be banned. If someone tries to make others aware about his activities or projects by posting several links or wall posts in Facebook groups, it is considered spamming. Having 5000+ friends or being a member of 200+ groups are valid reasons for banning you. In case, if you are banned, you will, mostly probably, not have a chance to get your account back. In that case, all the important data in your Facebook profile will be lost forever, including your notes, photos, friends list, and their contact details.
It is always better to start a blog in blogger or similar free blogging providers and then you can import notes from the blog to Facebook. In this way, you can make sure that your notes are safe, at the same time, they are shared with your friends via Facebook. Same applies to the photos. You can share your photos in Picasa or other photo album services using Facebook.
The moral of this story: We can use Facebook to share, but should have the original material somewhere else safe. Facebook is not a place to store your data!