Matrix - Is it a reality

I always thought about it after seeing the Hollywood blockbuster, Matrix, and its sequels. More so after reading this page, The Matrix - Our Future, from self procliamed cyborg, Kevin Warwick.

Now, I have a very simple point (or question) to put forward:

How can we assure each other that we are not already in a Matrix?

The main theme of the movie is the assertion, being inside a matrix means that you don't exist physically (but as a thought, a feeling a dream or whatever you want to call it). And although the machines have put all humans to the virtual world, nobody recognises it, and all are happy to be inside that virtual world.

The fact according to the movie is, that humans inside the Matrix are fed a storyline into their brain by the Matrix, that makes them believe the Matrix to be the actual physical world.

Now here again, how can we be sure that we are not already being fed by that storyline, and the Matrix is making us to believe that it is real.

(I just hope Smith is not an RSS subscriber to my portal )