We had a contractor in the other day who's been given an iPad by one of his clients. He was showing everyone in the office when I came over for a shufty.
"It does this and it does that, and because it's Apple it's impossible to get viruses or hacked," he says.
I couldn't hold my tongue and had to tell him that he was spouting utter rubbish and that any OS can potentially get infected and there's no such thing as a completely 100% secure OS and that mostly it's the users that install malicious software and breach the OS's security to allow the virus/malware to gain a foothold.
He did try to argue to I was wrong but quickly gave. Fairly sure he still thinks he's right.

Reminds me of an episode of Mythbusters where they were given a top end fingerprint reader door lock which checks the print and checks that the finger is living flesh and blood.
They built a fake finger that mimicked the vital signs of a living finger and beat the lock.
They even tried placing a finger print printed on plain paper and held against the scanner. That worked too!

Never assume anything is 100% secure.