AT&T SIM card

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?

Keep the sim card,you can use it in your new ipad3.It's not a good idea from a security standpoint to include your sim card when you sell the iPad,that's why the original owner removed his sim card when he sold the iPad to you.

The SIM card stores info that is NOT protected even if you wipe out everything on iPad back to factory state. As scifan suggests, keep your SIM and use it in your next iPad. The buyer of your old iPad can easily get another SIM card.