The airlines and the government do not track the waiting times of flights that arrive early.

The government does not track hate crime statistics, although they are relatively rare.

The government does not track the numbers of citizens leaving for abroad.

However, these present a privacy risk because they allow the mass transit operator (and the government) to track an individual's movement.

With "do not call," you and the government can positively track who called whom and when.

But Iran's government has been taking other steps too to discover dissidents and track their movements.

This way, the notes left less of a digital trail that the government could track.

And while the federal government does not yet track these types of deaths in a comprehensive way, they seem relatively rare.

The evidence is so far mostly anecdotal - the government is not tracking the moves.

There are no precise statistics on the age of riders, but the federal government does track those who die.