Passive/Active Rigid Bodies ...
 

Can an objects Passive Rigid Body attribute be changed to Active or the course of an animation sequence. I have a push pin holding a cloth to a wall through the use of the Point To Surface ncloth constraint. This obviously requires the push pin to be a Passive Rigid Body. However, I need the pin to fall away allowing the cloth to drop to the floor. This would require the pin to be a Active Rigid Body, with the floor being the Passive Rigid Body. So, can I change the pins Rigid Body status over time?

Yes.

There is an active option, check the channel box.

Cheers