Not having password protection on a smart phone leaves you open to information theft, jail-breaking and injection of spyware.
“Why does this trick exist?”
• It is a software loophole.
• It is a programmer’s shortcut they forgot to patch.
• It is a programmer’s Easter egg.
• It is a law enforcement backdoor never meant to become public knowledge.
Interesting question. You decide.
FutureWatch: The ability to create passwords longer than four measly digits… which is only a pool of only 10,000 passwords. ~Kevin