A man with a pick-axe and a sense of direction could go where he liked just by knocking down forgotten walls.
But neither will knock down walls with his bat.
Who is that down there knocking down the (stone) walls?
The answer, of course, is more closet space - but how can you create it without knocking down walls or moving to a new home?
The legal system can force open doors and sometimes even knock down walls, but it cannot build bridges.
You do this by moving around the stage, knocking down walls, and using your surroundings to keep yourself safe.
Victor Green is separating himself, rising and knocking down walls.
Tanks can knock down walls and other obstacles to open new paths.
Some schools have even knocked down walls to increase the space.
People are knocking down walls and, in the process, destroying the character of the neighborhood.