Several cards are "stickers". To test, I ripped the "sticker" of a Night Maintenance (holo). Underneath was a shiny surface. The NM was Transparent in some parts, allowing the shiny part to show through the sticker. I had a friend with something like this, only a Blaziken PK. These are not fakes, they are just cards that didn't fully get printed.
I have some cards that the sticker is up a little at the edge, but as long as it is in a sleeve, it is OK.