Now that I have said that about vintage clothing sellers, I must add a disclaimer. If a vintage seller scams a buyer in any way by transfering tags from one item to another and/or claiming an item is "vintage" when it is a new item, then that is dishonest. I do not condone that type of behavior. On the other hand, if they want to "glam up" a vintage piece by bringing it current with some new accessories, new shoes, new scarf, new hat, that's fine!! That is what "vintage" means. Re-purposing a piece to bring it current.
Lately one particular eBay seller has been lambasted for a "possible" action of switching labels from one vintage item to another item. It's hard to prove it. I see the labels; I see the trail. But it still is not enough proof that this happened. It could be possible that a lot of YSL labels were crossed out with red marker so that those items could be sold in a discount store. I have been a shopper for many years of discount clothing: Filene's Basement, Steinmart, SYMM's, TJ Maxx, Marshall's, and I know that those retail venues are sometimes asked to cross out the label of famous designers. Who knows? Maybe, just maybe this could be the explanation.
Don't be so swift to blame guilt. Be wary. Be careful.