[Tag that says TRACKING! (deploy mode)]

In my residence I see a floating tag that says TRACKING! (deploy mode) Its nothing I have added...help ...what might it be and how do I get rid of it?

[What does it mean to "follow" another avatar?]

What does it mean to "follow" another avatar?  I dont mean walking or flying in world.  Ive had people get messages that I'm following them?  I have no idea what that means?