1) You can guarantee you're using 100% authentic batteries?
2) You're 100% confident the batteries are brand new and haven't been used prior to your application (ie abused in any way)?
3) The batteries are being used for their designed/tested purpose?
4) You can guarantee that your mod isn't faulty or about to malfunction?
I'm not saying you don't look after your batteries, I know I certainly do:
1) Bought from a reputable eBay seller recommended on the site
2) Only using batteries which meet the required ohms law requirements
3) Kept and carried from A - B in a dedicated case
4) Only charged with a XTAR VC2 charger
5) Never left to charge overnight or left on charge once full capacity has been met
However, am I confident I can answer my own questions? Probably not..
Yes, a mobile has the potential to blow up too but let's be honest we're not talking about a £30 mod and a batteries bought from relatively "unknown" distributers with a samsung/lg stamp on the side. I dread to think how much the big mobile manufacturers spend on battery safety, testing etc.
At the end of the day we're all at the mercy of battery/mod reliability. There is no guarantee that even if you care for your batteries properly you're not at risk of malfunction. Ultimately though it's a risk all of us vapers are willing to take (me included).