When I lived in Spain during 2002 my friend came to stay with us for a week. He booked a return with Ezy from Gatwick to Murcia. We dropped him off at Murcia for his return only to get a phone call from him to tell us that his flight had been brought forward by several hours and had gone. There was no way they could notify him as you don't give holiday addresses etc. nowadays and we didn't have internet to check at that time. Trying to check with an airport like Murcia by phone was an impossible task then so we didn't usually bother, we just turned up a couple of hours early usually. It never occurred to us that the flight could be brought forward by that much. We always worried about delays. We had to bring him back and he didn't get away for 24 hours on his (free) rescheduled flight. I say free but he had to pay for the flight and then claim the money back which took ages. Fortunately he was retired (and had a credit card) and so the delay didn't matter too much but I understand this has happened often.