First off, if you received a battery in the battery recall program where Apple sent you a new battery and you have not sent the old battery back.....you are stealing. This isn't an issue of will it blow up or not, it is an issue of, if you don't send it back you are a thief. Why do people think it is okay to keep something that isn't theirs??? Apple sent you a brand new working battery....now send the old one back.
Whoever said they kept their battery and it works fine as a backup, especially on plane flights......you are a moron. There was a recall for a reason....I don't care if only 2 blew up or if, "it probably won't happen to you".....why even chance it. Apple isn't accepting a few million dollars in replacement batteries for fun!! It must be a real issue.
Stupid people cause pain to normal people. Mentally, physically, and emotionally,. They should be banned from existance.