Yes, you're probably right, but the original observation is getting stale and one wonders what the occasional passing policeman, users of the immediately opposite shop, and residents whom the box actually serves (not my street), have done about it in the mean time. I was quite prepared to report it initially, but now it seems like a less valuable use of my time.
They don't make it easy - the identification label on it is illegible. Wouldn't it be a good plan to put a phone number or some kind of contact details on all these boxes?