The phrase is often used metaphorically to complain about overpricing, not actual theft. Paying double for popcorn at the cinema feels like daylight robbery.
Pro Tip 2/3
Informal Context
It's used in casual speech and could seem out of place in very formal or serious contexts. I'd avoid saying 'daylight robbery' in a legal complaint; it's too informal.
Pro Tip 3/3
Emotional Charge
Expresses frustration or disbelief at the high cost of something. They charged me ten bucks for water; that's daylight robbery!