I have seen a propane explosion and fire out on the farm and it was not pretty. This was a leak that was accidentally ignited.
My problem with a propane tank is not about accidentally shooting it while defending against a home invasion, but a sniper with a high powered rifle with certain types of ammo, not shooting the tank once, but multiple times to set off either an explosion or a fireball and fire.
Go to You Tube and see the show of Sons of Guns or Red Jacket with the folks from Mythbusters,,, it can be done.
Propane tanks to me are a security risk.
That is why I have thousands of sandbags and plenty of shovels and a dozer at my disposal, if things were to go South, and I had to defend a fixed perimeter, you can bet that perimeter would be defended by a berm or sandbags or both.
Should Normal People lose any sleep over this,,,probably not.
Life Member,,,Military Order of the Purple Heart, Veterans of Foreign Wars, American Legion, Amvets, Disabled American Veterans, 173rd Airborne Skysoldier Association, National Rifle Association, Member,,,IDPA, USPSA, Iowa Sheriffs and Deputies Association,,Website http://www.handgunholsters.net