that DOES suck. Darned thieves!
My hubs works for the USPS and he said it happens a LOT this time of year. Thieves will follow the delivery trucks and stake out houses and steal gifts. He's even spotted suspicious cars and called them into his supervisor before. Crazy! Leave a note for your carrier (USPS) and they will bring them back to the office (or they should). Makes it a bit of a pain to go to the PO to get them, but at least you know they won't be stolen.
Dastardly thieves!!