This thing is terrible because it doesn't check the trust lists, making it the ultimate griefer weapon. It also spams the chat a with "that is not a brick" uselessly.
getTrustLevel(%obj1, %obj2); returns a value 0, 1, or 2. 0 = no trust, 1 = build trust, 2 = full trust. You can pass it pretty much any 2 objects. The projectile and the brick it hits would work well in this situation.
If this doesn't get fixed in the next few days I'm deleting it.