In Ontario, Canada, we used to call them album crates, for they fit LP record album sleeves perfectly. 
And the album filled crates made good supports for bunks over desks in student housing.
The wood used in CHEP pallets is also high quality hardwood - locally around here it is commonly a jarrah, but i’m sure elsewhere a variety of hardwoods are used. Probably an oak in the USA.
so the actual wood value in the pallet is not insignificant. There was a shady business running around my city where the guy would take chep pallets off your hands for $4 each, no questions asked. I’m guessing he busted them up for firewood or repainted them and onsold as some other brand.
So theft is/was rife.
I saw Chep had a worldwide income of over $5 billion USD in FY2016. Even assuming a tiny percentage of pallets are being charged for that don’t exist - a tenth of 1% for arguments sake - that’d be millions per year.
Why would you break them up ? You can sell them… well you are returning them for a payment of the cost of returning them, of course… but who knows if you are returning them to the correct source ?
Why are you even getting CHEP branded pallets ? See, if your supplier is giving you CHEP pallets, they are billing you for the cost. If you negotiate a new supply contract, you might ask for the cost of the goods to go down ? But then you get on the hook for the cost of the CHEP pallets, you need to ensure they are swapped when truck delivers, or you get them back to the supplier somehow ? Or you give the supplier a receipt, telling them where to tell CHEP to go get them from.
Basically, the delivery truck will either want to be swapping CHEP pallets, or leave without a replacement only if its covered by the sale/delivery contract.
This is fascinating stuff, I’ll only add that I used to work in customs clearance and the biggest issue with agricultural pests comes from the pallets that goods come in on, particularly from China. Pallets are slapped together using local and poor-quality wood, they’re certainly not kiln dried or fumigated the way CHEps are, and I’ve seen larva dropping out onto the floor as cargo was moved. The goods were fine, but the pallets kicked them into secondary.
The ones that very occasionally got used for firewood at several of the factories where I worked were the ones that had broken up due to old age or accidents. People didn’t break up perfectly usable pallets, but the people who’d normally take them didn’t want broken ones, so the broken ones got broken up further and used in traditional “broken wood item” fashion.
This has absolutely nothing to do with the CHEP business model, but yes, it is possible to retain a right in property even after that property has been sold.
For example, Fred got a job in the quarry, then bought a house, then married Wilma and transferred ownership of the house to himself and Wilma jointly with right of survivorship, and then they had Pebbles. Pebbles grew up with them in the house, and eventually moved out to become a rock star.
Fred ate too much fatty brontosaurus meat and died of a heart attack, leaving Wilma as sole owner of the house. Wilma then married Pebble’s childhood friend Bam Bam, who was no longer a child, but was still a couple of decades younger that Wilma.
Wilma was worried that she could no longer outrun Dino’s pack like she used to, so she sat down to carve a will, but she was of two minds as to who would get the house. She felt that it would not be right to give it to Pebbles and kick Bam Bam out on the street, but she also felt that it would not be right to give it to Bam Bam when it had initially been bought by Pebble’s dad who had assumed that it would eventually end up in Pebble’s hands after both he and Wilma died.
Wilma’s solution was to make a will saying that when she died, the house was to go to Pebbles as the new owner, but Bam Bam would have the right to live there until he died – what the primordial lawyers rising up out of the slime called a life interest.
Have a look in the loading dock of any supermarket; there’ll a couple there for smoko time. 
My wife’s milk supplier certainly does charge her for milk crates, and they give her a credit if she returns them for reuse. Maybe other companies do it differently, though.
Another example is these crates which hold 8 bottles of 2-liter soft drinks. Many people, including many store clerks, assume that these are available for the taking. But the soft drink companies don’t agree with this.
I once found this out when I was buying 8 bottles at a time, so I just took an entire crateful and put it in my shopping cart. (It’s a lot easier to carry a crate than to deal with 8 individual bottles.) A Pepsi guy who was stocking the shelves at the time walked over to my cart and removed the crate. I asked him about it and he told me that the crates are the property of Pepsi. But I have been told multiple times by store clerks (both before and after that incident) that I can take them.
Not surprising because of the rate of loss. A few years back there was a raft of thefts of plastic crates because the polypropylene is valued to be cut up and reformed into new products. And of course as already mentioned people take a lot of these for storage and make-shift furniture.
The grocers don’t care because they aren’t required to keep track. The drivers will get lectured once in a while about recovering the containers. I have taken them home from the grocery and then return them later on but I have a couple in the house. At most it’s just some petty theft for a soda carrier but a lot of people have kept US Post Office bins and bags and that is (allegedly) a federal crime (although I doubt the Supermax prisons are filled with mail bin pilferers).
The owners of the containers have to weigh the costs of recovery against the potential loss. Most containers don’t cost all that much but a major supplier could lose thousands of them every year. The CHEP model is attractive because they take over that risk. Unlike pallets though, milk crates, soda carriers, and the like that are delivered to retail stores sport the name of the supplier. They may not be as attracted to using a generic container when they’ve invested so much in name brand recognition and promoting the benefit of their particular brand over similar and often virtually identical products.
I’ve actually had an issue with the milk crates too.
The milk crates in my area say explicitly that they are the property of the milk company and anyone who has one should call such-and-such number to return it. I’ve never taken a milk crate home. But some local grocers who deliver groceries sometimes use the milk crates to deliver things in, so I ended up with a few in my garage. I called up the number on the crate and told the guys they can come pick their crates up at my address. But they told me I had to bring them to them. I wasn’t willing to go that far, so I just dropped the matter.
That shows how little they care about an individual crate. Just one crate doesn’t cost them much, but when they have to reorder a truck load of crates (stacked on pallets maybe?) they’ll feel the pain. I guess they could ask you to drop them off at a nearby retailer but they may think you wouldn’t bother doing even that.
I just wonder why they don’t go the tried-and-true “bottle deposit” method, rather than the “litigate any time you find someone in possession of a blue pallet” PR-killing routine. I guess since their customers are all large manufacturers and distributors, they don’t really care what the average joe thinks of their business practices.
CHEP is just like the truck that hauls them – you buy and sell what’s on the pallet, but the pallet remains the sole and exclusive property of CHEP, just like the truck and trailer are moving your stuff around for a fee, but you never at any time own or even rent them, you just pay for the service.
Re: milk crates: all the ones I’ve seen in the US have dire legal warnings on them, I guess because milk is heavily government-subsidized. If you steal a heavy-ass blue pallet you’re stealing from a European company, and they can go after you in civil court; if you take a milk crate home you’re stealing from the taxpayers, and the government will make it a criminal casel
If by “heavy-ass blue pallet” you’re referring to one from CHEP, note that it’s an Australian, not European, company. And I think in the US the milk crates are owned by private companies (the dairies), not the government.
The US government has no direct involvement in milk crates. They are (often) 100% property of the dairy. The Feds would only get involved if you stole a bunch of them and took them across states lines (maybe).