Has anybody done this to guard against buying forgeries?

[Leon]

I have first hand knowledge that the scammers are not targeting collectors such as frequent this board, for the most part. They are selling on Craigslist, ebay and locally at shows etc... And they are doing it on the cards everyone knows about ie.... '52 Mantles, '09 Jackson rookies, '86 Jordons and Goudey Ruths etc... A lot of inexperienced people know what those are and can do a quick Google search to see they are valuable and what they sell for. Then, when they see a '52 Mantle, in a PSA 4 holder, for 5k, they jump on it. All the while the card in the slab is either fake or altered and has been put in the slab fraudulently by the scammers. If collectors get feedback from us on the board, or other hobby veterans, then they (most likely) won't get taken. It's the greed factor the scammers are counting on. I have spoken to the ringleader of a large fraud ring in the hobby for over 2 hours, within the last 2-3 days, on multiple calls. He is the one that is behind the Den Prak stuff too..but this guy is allegedly in Mexico and is very slippery. He has allegedly had a warrant for his arrest for a few years.