Facebook unethical?

Facebook has hit the news again.

Anna Lemind wrote about the hidden psychological experiments they conduct.  Without informing their users, they have been gathering statistics about the positive and negative emotions expressed by the users through keywords and emoticons.

Violet Blue said that Facebook "tampered with the emotional well-being of 689,003 users" as its experiments sought to find ways of spreading, or avoiding the spread of, emotions en masse.

Peter Aziz reckons that Facebook's mobile app gives the company too much information about us.  The app tells Facebook where we are, who our contacts are, what their contact details are, what we photograph and text to each other.

What do you think?

Are these guys unnecessarily cautious?  Is Facebook unethical in the way it handles the information it carries on its servers?  Are they not allowed to perform data mining on the information that sits on their hardware?

Or are they fine to do what they want with data that we have given them?  We did, after all, agree to give them that data when we signed up to use their app and their platform, didn't we?

Has the company overstepped its boundaries, or are they fine?