I Purchased a used iPad 64g 3G about a year ago. I've been a daily reader of this forum and totally enjoy the information and knowledge from the many experts. I plan on selling my iPad 1 and getting a iPad 3 upon release. My iPad 1, used, came without a SIM card so I purchased one on line. I don't believe I'll have a problem setting up the iPad 3 from my backup, but have read on forum to remove and keep the old SIM card. I've also read where the iPad 3 possibly may have 4g lite and perhaps one iPad could be used with either AT&T or Verizon (different SIM card) The question is if there is a security, or other concern leaving the SIM in the iPad 1 as I plan on selling it before I get the iPad 3. I also would like to preserve the option of keeping the 2 gig plan on new iPad. I would reset the old iPad to factory prior to selling. Would this protect my AT&T information associated with the SIM?