Yeah I doubt that much water is stolen from hydrants in the US. I have heard of business using it, but as I understood it they are required to get permitting and pay for usage by monitoring their flow, at least in California.

Usually it happens at the geographic fringes of civilization where cisterns/tanks get filled from municipal water supplies. Not people running a hose to their house.

But there’s also a lot of truck-delivered water used in construction/dust control.

No shortage of reports/charges: https://duckduckgo.com/?q=fire+hydrant+water+theft