I don't see people willing to share their data (with companies like Google) as the issue. The problem I'm concerned about is that there is a decreasing amount of choice in the matter. While you ultimately have a choice in a lot of these privacy-concerning cases, it's increasingly difficult and annoying to do so. People eventually cave and Google (et al) profits greatly by pushing them to do so.
> There are many different areas which would be improved greatly from more data and would be to everyone's benefit.
I agree wholeheartedly that data can be used for some really fantastic things, but it should not come at the cost of choice/freedom nor privacy.
I'm also thinking about it in terms of opportunity cost.
Namely, companies like Google and Facebook are poisoning the waters for would-be data-based companies that would have much greater impacts on quality of life for everyone. While they help some things at the moment, I think they are ultimately hurting would-be bigger and better data driven endeavors.