Grabbed a bag of salt and vinegar crisps from the box the other day. We usually buy multipacks of McCoys as my autistic son usually won't eat any other crisps than cheese and onion McCoys!
The bag felt heavier, like there were definitely more crisps in it so I weighed it. The nominal weight is 25 grams, this bag weighted 52 (!) so clearly a double dose went into that bag. I just hope no poor sod got a completely empty sealed bag in their multipack!