When people start getting tickets, they tend to change their behavior.

When the signal goes red, our system becomes sensitive to people who run the red light.

You're going to see more happening in Washington.

People don't change their behavior unless it makes a difference for them to do so.

You can't explain this dramatic change in behavior by saying that people are just looking for the best payoff. People gave up payoff to follow the cooperative norm.

People are defining new rules and new behavior for what's personal and what's private. Technological change leads to social change, but there's always a lag.