the majority will stay using Facebook and Google, because they have advanced technology, they have worked hard to make the user experience mush better, and they give all of that for FREE. I believe that 80% of people don't care if some agency see what they do, because they don't do much, and they seek for the cheapest method to stay entertained.
For Google, it's obvious that it's leading the search technology on the internet, and a such leak won't make it stop spying on users, but for Facebook, and even its huge base of users, this leak can make it change its privacy policy if and only if it is threatened by a new social network (it's not easy but possible), it's a matter of money, people search for the cheapest and the better technology.
the rest of population which is 20% for me is the people who believe in the right of privacy and they are ready to make some sacrifices (pay money, or use less-tech encrypting methods).
in general, I think people will accept that by time, because if someone have the intention to be private he can, but if he just want to talk with his family, this is not important, and any agency haven't interest to spy on that.
it is helpful is most cases, but it has to be just a tool not a goal. a developer can reach the same thinking level just by working on its personal projects and by searching and reading about algorithms. However timed problems improve rapidity, which enterprise-oriented skill.
but the goal behind TopCoder problems should be improving thinking skills, not preparing interviews, I think.
Because not the actions which determines more our future, but the intentions, I think