I'm not a facebook person either. Besides the things that you said (and which I agree with), I am very leary of a never-ending electronic profile being aggregated for (or against!) me!!

I really get concerned about privacy - for the under 20-year-olds especially. They have no idea that everything they type is archived somewhere - by some entity. And with data storage as cheap as it is and retrieval mechanisms as sophisticated as they are...these kids will have a virtual history of their lives available in perpetuity to anyone who wants to pay for it.