I had a Joy eGo that used once or twice a week. I plugged it up to charge it at work, and it exploded today. I was not beside it when it exploded, but apparently it shot sparks like a roman candle into the air.
There are other reports of eCigarettes exploding, but I’ve never had a problem until today. If you use an eCigarette, be sure to keep an eye on it when you charge it!