Exploding phones

Don't you wish you had rigged your phone before it was lost?
Don't you wish you could do it?
Why are my countrymen so cheap?
What happened to moral values?

Even among friends, the belief that you could keep what you find is prevalent. If I share my story (of returning lost items), I won't find praise.

My tally of lost items
===============
Phone1 - Taken together with my bag at the depository section while I was taking a water ride. It was triple-ly painful as the bag was a gift and the loss was no fault of mine.
Phone2 - Left on the table at a wedding. When I discovered my mistake, I ran back up but it was too late.

Wallet1 - Left on the bus. Returned to the police with all cash intact but the farecard was gone. I did not point this out to the police.
Wallet2 - Left on an arcade machine. Recovered by a member of the public in a toilet. All the cash was gone.
Wallet3 - Left in my unlocked locker in my bunk. After I made a police report, it appeared under my pillow.

Watch1 - left on table as we were having turnout drills. I was quite upset as we were supposed to comrades - who shouldn't steal from each other! I did not report this. After this loss, I no longer carry a watch.

What I found
=========
Wallet(i) - Same arcade as where I had lost my wallet. My classmate lost hers this time. A kid whom I was on friendly terms alerted me to where the thieves were hiding. We tracked them down and sorry to say it but we intimidated them (threatened to call their school, not physical violence) to return the wallet by the next day as the mastermind had fled the scene.
Wallet(ii) - Found on the floor at the reception area of Ngee Ann City - where the big Christmas tree stands annually. Passed to receptionist.

Phone(i) - Found on the sofa outside our classrooms. Went into the other class and asked for the owner. Luckily, he turned out to be the true owner as I had forgotten to authenticate him. (He called me back by the number I had given his mother).
Phone(ii) - Found on back of taxi with GaGa. Taxi driver took us to where he dropped off his last passenger and we returned it.

[Conclusion]
No one steals the wallet itself. So build a phone that looks and functions like a wallet. And in the event that it does get kept, it would blow up when the secret cipher is not keyed in daily, costing the thief some fingers.

-4 days