I went to a children's theatre show where three children were sitting in front of us, mesmerised by the performance. Then the mum got out a mixed bag of sweets and started asking each child which ones they wanted! I can (sort of) understand using one or two unwrapped sweets to distract a child from spoiling other people's enjoyment - but these were happy, interested children.
Also - since I'm ranting now - when did theatres start letting you take drinks from the bar into the theatre?