Catalytic Converter Theft...

I've seen a few news links about catalytic converters being stolen from cars. Tonight one article revealed data from insurance companies stated what was thousands per year are increasing in numbers. One of the most targeted vehicles is the Ford F-Series truck. The truck is high enough that someone can slide under with a wrench and unbolt the unit in a few minutes.

Personally, I had an engine fail on my 2014 Hyundai Veloster caused by a piston ring that sent 3 quarts out the exhaust. My mechanic found a used engine, one recovered from a rear end collision. It wasn't running correctly and the suspect was the catalytic converter had clogged due to the oil. We could have shorted out the sensor, re-piped the exhaust and reprogrammed the brain, but that had some restrictions. I didn't want to drive a car with a tampered exhaust system so I bought a re-manufactured catalytic converter and the car ran like it did before the engine blew up.
At that time, new catalytic converters for that model were around $1,500 and re-manufactured around $500. Either way, it was a big chunk of money.

I did find flaws in some the stories I've read.
Most cars have alarm systems that are set off when you bump the car.
So, how is it possible someone can jack up a Honda (for example) and unbolt a converter without setting off the alarm?

Some stolen converters are used to replace defective ones in other cars while other are sold for the precious metals they contain.

Okay, police have suggested engraving them with a unique traceable number.
In the real world, just like stolen guns... grind off the number.
I believe possession of a gun with a tampered serial is illegal, but I doubt there are laws to cover converters.

If it's so easy to unbolt a converter... SPOT WELD the joints so only someone using a grinder could break it loose.

Maybe more thought needs to go into a method to deter the business of stealing catalytic converters...