The reckless courage of guinea-pigs

As my regular reader knows, I recently lost a large tree. During the removal of the stump, a curious fox turned up to check out the proceedings. Now we've known for some time that we have foxes living in the woods at the top of our garden, and on one occasion we even saw it after dark examining the guinea-pigs' hutch outside our back door; but this was the first time we'd seen it in daylight. Our friendly neighbourhood stump remover offered it a sandwich, which it ate from his hand.
After that, it wandered over to say hello to the guinea-pigs. It has evidently done this a few times before, since the guinea-pigs showed no fear and came out to face it down from behind the safety of their bars. This raises an interesting issue of security versus freedom. Is it cruel to lock small animals up in hutches? Wouldn't it be better to allow them freedom to become someone's lunch? I trust you will now forgive me keeping them securely locked up.
I would not expect anyone to believe this story without photographic evidence: