A LOT of flights are delayed because US Customs sees no problem with stalling incoming passengers on their entry back into the USA. When we tell them (as crewmembers) we have a flight to catch, they snicker and say, "well, I guess you'll just be delayed, won't you?" This it typical government hypocrisy. They make us late, and then WE pay for it in bad press, refunds, missed connections, etc. When USA Today publishes the "most delayed flights" (along with ontime rankings) they always seem to forget that ATC is responsible for the majority of them. The airlines can't make money if the flights are sitting on the ground and can't be released, but the public THINKS it's all our fault and that we WANT to be delayed for whatever reason. Guess that's what happens when you can "spin" the story.