Third shiny penny on my doorstep?

I would be very careful. You are right in letting your mind wonder because better safe than sorry. I'd look into whether there is any gang activity in your area because this is typical of gangs. I've heard of the shiny penny as a signal, as well as leaving your mailbox halfway open, as well as placing a broken branch on the front lawn so that it can be viewed from the street. They use these signs to signal each other to rob the place or to signify that a woman is alone at home and that the man isn't home. I've had my house broken into both while home and not home. The law enforcement might think you're paranoid or loony at this point but definitely keep your eyes peeled. Look out for signs. My experiences were terrible and very costly to replace my stuff. If after a while you don't see signs you'll be fine. Sorry that you're in this situation :(

I'm not sure how marking it with a penny proves anything at all as far as marking the house. Because some times you might miss it entirely or not pick it up. That's horrible marker. Just get a gun (Cause we have that freedom for now) and learn to shoot it at the range. Then in the event that some horribly stupid person breaks into your house while you are there because they thought marking it with a penny was a great plan you can ask them politely to leave with the barrel of a gun in their face. They will most likely depart the premises quickly with all due haste. Or you can hold them until the police arrive. Or you can shoot them. So many options!

I'd be curious to know where you heard that one. There are some simple radio plans, but that's not one of them. For one thing, you'll need a power source. Even the batteryless shake-a-radio devices have a capacitor. You can get power from a potato done right, but I don't see that on there. You also need a really long wire to be wound for a tuner (never mind I see nothing there to adjust it). I suppose you might somehow make a wire out of the aluminum foil... but you'll need heat to draw it out. If we're going with the myth, where's the heat source? I don't see a torch on the list. And what's the friggin' penny and plate for? Busted.

Yes

No but i do tell you this, according to the second amendment every American has the right to bear arms. Put the house with alarm or video survelliance and for extra protection its always good to have a fire arm

Pick up the penny - and leave them a nickel. They'll know you're watching for them.

No, I have never heard of this, but keep the pennies they will add up.