What about the belief that you can't selectively invoke it? That if you break that silence then they can compel you to answer everything else from that point on

What about the belief that you can't selectively invoke it? That if you break that silence then they can compel you to answer everything else from that point on? How's that work? They might as well abolish this right anyway. As if every device we ever touch won't testify against us in the first place.