True, this happened this week it seems. There are people who believe genuine lithium iPhone batteries can be tested by biting on it. No idea what's the logic behind it.
Pure lithium will instantly react with water, or even moisture in the air; the lithium in lithium ion batteries is in a less reactive compound. Mistreatment during charging or discharging can cause outgassing of some of their contents, which can cause explosions or fire.
Crazy people. Thanks for the comment though. Cheers!