Package delivered late evening; checked mailbox for locker key; couldn't feel for it.
Assume I couldn't find it in the darkness; decide to check again in the morning.
Find package on front doormat. Opened.
Luckily, nothing was missing as the product itself was unopened, but this is a situation where I don't know who to get more angry at. It's either me for being incompetent enough to not bring a flashlight, the postal service for (potentially) delivering it to the wrong person, or the theoretical "wrong person" for snooping through someone else's stuff and not bothering to leave a note about it.
But honestly, it's hard for me to be angry at the moment, I'm just happy that I actually got it.
...I know this paranoia is unrealistic, but, damn, I hope I didn't catch anthrax.