Just remembered one. My family won a 30 lb. lot of bionicle off of eBay. Not only did the seller not realize we had paid for it (which delayed the shipping for about a month), but they decided to send it in two separate boxes. Both of these were very minimally packaged. You can probably guess what happened. One of them likely split open in the mail and got lost. 15 lbs of bionicle basically gone and likely auctioned off later to someone else.(What happens when your packages can't be identified or sent back) It's annoying, but at least now I know to remind others that they need to package things well (as well as buy from credible sources). The buy was pretty much a steal, so the stuff we did get was still worth what we payed for it.
Needless to say I was pissed for a while. That other half also had some peices I was looking to building with.