> Since QR codes are easily known, it would be trivial to send mail using someone else's code and bill them.

Did You see the part where you stamp the package, AND THEN it asks you on your phone for the address to send it to?

It would be no more hackable than a bank account that sends a code to your cell phone before it lets you log in.

That will not hurt them.

Writing software to wipe all Microsoft installs will hurt them...too bad it's illegal in some places.

Paint ballons may not stick to the glass, and require you to get close to throw.

A rifle can take out a camera at 300 yards.

You're not familiar with practical shooting sports. Yes, gamifying it makes some people more efficient killers.

Without gamifying, people take killing to seriously. They just learn what they are taught, and worry about screwing up.

When we made practical shooting a game, people looked for ways to win, and we invented CQB.

What do nuclear reactors have to do with jamming?

RF jamming just means transmitting noise on certain frequencies, or on all frequencies, or on all frequencies except the ones you plan to use.

Frequencies, antennas, transmitters, and locations are relevant. How it's powered is not relevant.

I'm fairly certain a TANK would be a metal box that would block out most RF jamming.

If I wanted to disrupt this, I would use a rifle (or shrapnel) to take out the cameras.

Yes, rewinding (is a player that rewinds softly, not in one that just maxes the voltage to the motor) then playing, then rewinding again is a VERY GOOD IDEA.

Also, not all players are created equal. With some tapes, you want a high-end player, with others, you want a player that can follow the tape's errant tracking WAY OUT OF BOUNDS.

I go to a GoodWill store, buy 4-5 decent looking VCRs, exchange the 2 that don't work, and try the same tape in all of them. You will find different tapes work better in different VCRs.

The problem would be that their loved ones DO depend on it. You have to get food, water, etc...all very quickly...all without injuring yourself.

99% of people would die if asked to be self-sufficient. Sure, you think you can make a part, but you are lacking the parts and tooling. If you did have those things, you would cut yourself badly doing manual labor for the first time in years.

After a day, you would be hungry, thirsty, tired, and stressed. The quality of your work would go down. This is a downward spiral that would not end well.

The problem with "circuit design, construction, metalworking, carpentry and most of the other building trades" is that You need the parts.

Where do You get the 3/8" x 2in aluminum stock? What about the end-mill?

> I've had at least two UPSes add injury to insult by simply dropping dead
> and failing to even act as a power strip, merrily cutting power to
> everything attached to them despite mains power being available
> (and every 'unprotected' device not even flickering).
> Thanks a lot APC...

What model(s) were You dealing with?

Hell yes! This is what I did at Ericsson.

1. Cell phone towers can be redundant, independently powered, and well protected (as long as the protection does not interfere with radio signals.) The link to the "network" does not need to be a wire, it can be a microwave link to another terrestrial site, or to a satellite.

2. We keep saying: keep cell phone towers in reserve (in large office buildings) with their own power supplies so they can be (literally) rolled out, connected to its other parts, and started up after an emergency. This is unpopular with the major telcos, since it costs money.

3. We pioneered the 8-hour/24-hour install at Ericsson many years ago. We would get notice 24 hours before a site was supposed to go live that such-and-such government wanted cell service at such-and-such location. We would strap the cell site to the bottom of a helicopter, and deliver it the next morning. 8 hours after the crate touched the ground, the cell site was active. It's nice to have a cable running somewhere, but more often than not, we depended on microwave links.

One more thing...and this is a FCC policy thing...We could create an "emergency" mode where a quad-band cell phone will talk to any network in range, and where the networks can even load balance between themselves (so no network goes "down.") We have the hardware, it would just be a software patch.

Under Texas Law, YES, it is illegal to proposition a minor, where a minor is anyone You are not married to who claims to be under age. Even if You can see via webcam that grandma is old enough, the second she says she's under age You stop or You become a felon. (I don't know about computer generated characters.)

(Chapter 33 of the Texas Penal Code)

Of course, Your laws might vary. Not all of use live in Texas.

I will not touch the issue of international "commerce" not being covered by the Texas Penal Code. If they guys with guns and uniforms say it's covered, who am to argue the Supremacy Clause?

This is what I would do.

There are hundreds of tutorials on interfacing (PS/2, USB) keyboards to AVRs and to AVRs with Arduino Boot Loaders installed on them.

A cheap LCD would let your students see their accuracy in real time (WHICH IS CRITICAL!)

Now for the tricky part: You need a microcontroller, custom PCB, LCD, keyboard, battery, and charger for $50. It can be done. I could even build in some tutor programs for that price, but the $50 would be just for the parts.

Given that the US nanny-state has outlawed pajammas that can catch fire when placed in the flame of an acetaline torch for 20 minutes, I wonder how they will respond when faced with clothing that can outgass, catch fire, and explode under the right circumstances?

Books are the wrong way to go.

Try groups that get togeather. (Ham radio groups mentioned on ARRL.org are a good place to start - everyone's an hobbyist engineer.)

Try web sites, like AvrFreaks.net. Try discussion formus on web sites.

First, You left a few things out when you only mentioned 3 nations. I can mention more than 3 counter examples:

Norway has Western Europe's highest gun ownership rate and the lowest violent crime rate. (http://gunowners.org/op0746.htm)

Mexico's strict anti-gun laws (compared to Texas) correlate to Mexico's higher violent crime rate.

Washington, D.C. has stricter gun control laws than does Virginia, which correlates nicely to the higher crime rates in D.C.

Second, gun deaths is the wrong statistic. Gun deaths measure every gangster shot dead by a cop. Only a delusional psychopath could confuse a rapist with an innocent victim. Try measuring the violent crime rate, and correlating that to gun ownership. You will get much more useful data. FFF has some great data on cities murder rates compared to their gun control laws: http://www.fff.org/freedom/fd0210e.asp

Third, Your numbers are for the entire USA, which includes places where guns are not available (e.g., New York City, California, etc.)

If you look only at murder rates in the places where guns are commonly carried, you get a very different picture of the USA.