Automatic tracking motion tracking / spotlight "ACCESS"

What is the experimental art of what happens when there is a spotlight that automatically tracks people walking in public places?

Below, that movie and a bonus movie.
YouTube - Real World Motion Tracking Part 2
http://www.youtube.com/watch?v=dftzq8zIPR0

A movie that understands what principle it works.

YouTube - Real World Motion Tracking
http://www.youtube.com/watch?v=kMZL9DHeIwI

In addition, here is a gun that tracks fully automatically.

Sentry Gun

Aimed and shot movies
http://www.usmechatronics.com/old_page/small/test2.wmv