I live online. That's a statement means different things to different people.
To people before my generation, that may mean I've made a choice disconnect from "real life" and spend it staring at a series of LCD screens.
To those within my generation (or neighboring it), it may mean that I've adopted the position that my job and life nearly require me to be tethered to a mobile device (phone, laptop, tablet) for pretty much every waking hour--standard exceptions for family events, medical moments, and Federally-imposed dead zones (airplanes). Sleep is not an excuse.
But, increasingly, being "online" is a default. A recent survey from the Institute for the Future asked participants "How many hours per week do you spend online?" Increasingly, the response to that question is: I don't understand the question. We are moving more to a culture where everything you do is online. The default is no longer "I choose to be online," it's "I live in this always-connected world."
The struggle for many people in my position (generational identification aside) is that, by living by default online, we still report to, are hired by, and deal with people who do not share or potentially understand that mindset. We still see stories in mainstream media outlets about "teens" (for large values of "teens") who post every intimate detail of their lives to social media. To these people, posting this information is not seen as a negative or a positive; it is a default. It just is.
I always fear that what I say hear (or on Twitter or Google+) will flow back to a person in my professional life who does not understand that those things, while me, are not how I am at all times. Having my entire life indexed is a challenge, despite Mark Zuckerberg's opinions to the contrary. (Sidenote: I avoid Facebook due to family.)
Someday this will change. In 10 years, hiding who you are to any degree online isn't likely to be as big an issue as it is now. I think it will bring other challenges, but the societal norms will change enough that damage to a professional career won't be so looming. At least I hope so since Google doesn't forget.