Nothing is secure these days, and as trusting as you want to be, DON'T!
Chain your camp fridge to the van wheels. Secure everything.
Losing a bit of grog out of the fridge is a very small price to pay in the big picture.
These leeches are opportunists. They are not taking an "innocent stroll" through the park. Daylight and dark - it doesn't matter to them. While they often operate at night, day time is not out of the question.
They'll steal anything even if it is nailed down. They flog it off for cash, usually to buy bigger and better drugs. They probably drink the booze.
Please take care. Look, lock, leave applies everywhere, not just the supermarket car park. Get familiar with your surroundings, the cars and vans and the people.
While we like to think we are in a safe environment, and want to trust our fellow travellers, unfortunately this world these days does not make that possible. What's yours they want to be theirs. Always look around. Cheers Chris

Yes Dave, what a catastrophy that would be, reminded me of Humphrey Bogart in the "African Queen" when Catherine Hepburn tipped all his grog out. It's a wonder she didn't end up in the drink as croc bait!

The look on his face was priceless .

Vic