I don't get why the keg deposit can be as low as 20 or 30 bucks when the replacement cost is at 4 times that. Charge $100 bucks for a deposit a see how many kegs go missing.
What have you ever rented that required you to put down the total replacement cost as a deposit? For many businesses that would drive off a significant portion of customers.
I guess the only two thing I have rented before were cars and keg shells. I didn't have to pay any deposit on the car, but I did have to give them my credit card and proof of insurance.
You can't find a keg deposit from a craft brewery in my neighborhood for less that $75 (cash), and some are as high as $150 (credit card).
I am not not not saying it is ok to steal a keg, but if the mega breweries were really worried about a lost keg they would raise the price of the deposit.