I check the cards myself for standard stuff, viruses etc. But never thought about how easy it is to “fake” the size of the card, or that a microprocessor on it could be compromised…or intentionally compromised from the manufacturer. I do like the idea of “hacking” the card to be used like an arduino and other micro-controllers. SD cards are pretty cheap so this could be a nice alternative to arduinos.
Oh the tool to test the card for fake size can be found here http://mympx.org/Downloads/p13_sectionid/2/p13_fileid/13.