It is scary I guess, but you hold responsibility as a user how volatile the situation is when signing up, they declare straight away that the TOS may change.
Hugo, logically... which companies exactly would provide funding to Facebook? Fruit farms? Flower shops? Musical equipment suppliers? No... Facebook is simply a data mining project in itself, justified with a useful product and communication system. The very nature of Facebook means the people most interested are in fact data mining corps. and internet/technology sector corps. like Microsoft.