What would life be like if everyone wore a spy camera that transcribed all conversations and uploaded them to various internet services all the time? If you knew everyone you ever talked to recorded it all and put it on the internet?
Once your data is recorded, you can't take it back 30 years down the road if you decide you don't like the direction the company has taken, or if privacy laws have changed to no longer be in your favor. The data is already out there. If you think changes in the TOS are bad now...
And your info won't just go to Google. There will be apps. You'll "Post this conversation to Facebook" or something equally stupid. Now fifty different niche websites are accessing things you said to your friend that you never uploaded. (Also, remember seeing in the news that some jobs require your facebook password as part of the interview process? What if that became more common? What if it wasn't just facebook, but everything you ever did, said, or saw happen?)
Our personalities will change, too. We'll become accustomed to constant and total self-censorship
People's data will be subpoenaed too, or just made available for general monitoring in some dictatorship somewhere. Maybe you once had a conversation with someone who later is investigated for something, and out of context your conversation sounds terrible. Now they investigate you. This investigation won't lead to a conviction, but it might fuck your life up for a few months. And that's an optimistic scenario.
I don't really believe it's stoppable though. We're not taking smartphones back. This is just a smartphone strapped to your head. We probably will tell people not to wear them in certain places, but how long will that last? We'll get used to it, like we got used to the TSA. Technology is only going to get more ubiquitous. Maybe we can fight fire with fire. The cypherpunks have been doing it for a while.
Play devil's advocate sometimes. Google Glass may end up being the best thing ever, but we should always question things. If the answer to the question is good, then it doesn't matter that we asked, but if it's bad... we'll be damn glad we did.