If you lookup:
fedex "Package not due for delivery"
which is one of the status messages you can get when tracking a package, you'll see a lot of postings asking about it.
FYI: It means your new toy has arrived in the city you live in, but will NOT be delivered today, because they didn't promise to get it to you until tomorrow. Whether this is to force customers into paying for express service, or simply a logistics issue, or a mix of the two, depends on your view of companies and I won't get into that here.
However, you'll notice a lot of the postings asking about it are from folks waiting for delivery of things they're very excited to get, often some big-ticket peice of shiny electronics. They're dying for Fedex to deliver it - they're so anxious and upset about the delay that they motivated enough to go online and search, and make ranting posts - all because their "toy" is delayed.
So we have particular emotional response, often about an upscale product, with a reasonably distinct search phrase - cool!
Yes, yes, of course you could say that the customers are mad about the percieved injustice of it, the Occupy Wall Street spin, or that sometimes the package could be really important for other reasons, which are certainly valid points. I'm not taking sides or passing judgement - and I found discovered this today looking for a friend's overdue toy - that's not the point. I'm just saying that I bet there's a good statistical correlation, and of course it wouldn't apply 100% of the time - which would actually be quite rare in such things.