It most definitely is not "a couple" of cases, it appears to be a thoroughly rampant problem that has destroyed any trust I have in buying items from Amazon. I personally received about 5 counterfeit/bootleg items before giving up on buying from Amazon entirely.

The US GAO recently did an investigation (admittedly not specific to Amazon, but it included them) and 20 of 47 items they purchased were counterfeit!

https://www.gao.gov/assets/690/689713.pdf