The most annoying thing Mouser ever did to me was send me a tube of QFN that appeared to be the loose chips repacked by hand. They were all turned 90 degrees. But I've seen gigantic piles of individually bagged components, before, and now I know it wasn't necessarily the result of my client clearing out a Radio Shack going out of business sale.
The other annoying thing is when you order the amount shown as "available," and select "one shipment when complete." Then they go to fill it, and they come up one short. Then your order never ships until they get new stock. Of course, it is also annoying when you get 99% of your order, then 1 month later you get that last chip shipped out to you. I think it should be obvious when you order 100% of what's in stock that they will automatically reduce it to what's actually in stock if they turn out to have 1 less available than shown, and send you a notice.