We started our experiment with some CRT computer monitors that were headed for the recycling plant -- they were stand-ins for CRT TVs (their construction is essentially the same for our purposes). For the first test, the author threw a TV remote with the batteries still in it at the screen as hard as possible -- full-wind-up, Major-League-Baseball-style. The CRT screen got a small scratch that rubbed right off. The remote -- well, the author never did find where it landed. It's somewhere in his garage.
For the second test, the author hit the screen with a 48-ounce (1.4-kilogram) lead hammer. He didn't just tap it, he swung and slammed the hammer into the screen repeatedly. The screen did get some nasty marks and scratches, but it wouldn't shatter. Finally, the author took a cutting tool directly through the screen. After several minutes of cutting, he still hadn't sliced all the way through the glass.
The bottom line? If you have a standard-definition TV with a CRT screen, and you're a particularly demonstrative Wii bowler or tennis player, you'll still want to use the wrist strap, but only for the protection of the Wii Remote and any bystanders, not necessarily for the safety of your TV. In fact, anecdotal evidence shows that CRTs can survive drops from garage roofs and from moving cars without the tube cracking, exploding or imploding (but they won't stop a bullet).
What makes CRTs so tough? For one thing, they're made of fairly thick glass, 10 mm or more depending on the TV or monitor [source: Society of Photographic Instrumentation Engineers]. Perhaps more importantly, they aren't just sheets of glass -- a CRT screen is a large vacuum tube, sort of like a giant light bulb. This gives it a certain structural strength that a flat sheet of glass doesn't possess. Indeed, the fact that there's a vacuum inside a CRT tube is part of the reason for the thickness of the glass. It needs to be strong enough to resist imploding. The bigger the tube, the thicker the glass has to be.
Of course, there are many electronic components inside a CRT TV, so subjecting it to serious impacts can easily damage those components and ruin the TV, even the screen isn't cracked. There may also be toxic compounds inside old TVs, and certain components can hold a strong electrical charge even if the TV is off and unplugged. Be careful with your old TVs, especially if they're damaged!
In other words, don't try our experiments at your own home.