The Raytheon Controlled Impact Rescue Tool (CIRT) weighs 100 pounds and can smash through concrete walls. The product has rescue in its name, but I assure you it'll be busting down all kind of walls where the primary objective isn't to save anyone. A little slow though Raytheon, because I've had one of these for years. It's called a jealous girlfriend. She thinks she hears another girl's voice on the other side of locked door/wall and she'll tear through it like a wet paper bag with a chocolate bar inside.
Worthwhile video of the unit in action after the jump.