Picture Card Reader

Picture Card Reader
Can a card reader to delete the photos off a memory card if you accidentally unplugged?

I was uploading photos of Kingston 1GB aa card into a 19-in-1 card reader for my mac GE when the power went off accidentally. I was preparing to go up (which means it worked in the first place) and I can not do it … I tested on a Mac and a PC and even tried to see if the images were presented in my camera. I'm usually an expert in technology but can this happen in reality?!

my card readers are based on my pc, but 2 I can not see why it would or should.

USB 43 in 1 Multi Card Reader SD MMC xD-Picture