I went down to pick some more today and they were almost all gone. At first glance, I couldn't see any at all - only those well hidden under leaves had survived. I picked a grand total of six. Even the partially ripe ones were gone.
This was more than someone having a quick snack. I'd say the equivalent of at least a couple of punnets was taken. Someone took those to sell - why else take all the half-green ones as well? (they'll ripen away from the plant, though they will never taste quite as good as ones picked when they're fully ripe)
Has anyone else had a theft of this kind? I wonder if the rising price of food is behind it.