"Act as if what you are doing will be on the front page of the New York Times."
In an analog era, there was some, but not much risk of that happening. In a digital era, the exposure opportunity on the scale (or beyond) of the NYT is omni-present...and it is going to affect EVERYTHING.
Some are paranoid about a "police state" or intrusive government, but more than that, it's your fellow citizens who will expose your individual and/or corporate behavior.
Remember the $1800 video I took? That's one example.
Today (HT: Seth Godin), I offer up some interesting/disturbing videos from the classroom. Teachers are now on the front page of the NYT.
What I may tell my kids as an updated version:
"Act as if what you are doing will be on YouTube"