Illinois is a little tricky because of the whole FOID card deal. However, there was a thread on here not long ago about a guy who lost his gun because its history caught up with it. The author of that thread also mentioned that if you have a police officer or any other person with certain privilages check the serial number and it comes back hot/red/flagged (whatever) they will be required to report it and you or the seller will still lose the gun.