To promote a phone insurance, Vodaphone and McCann Erickson Romania hired professional pickpockets (I would have love to seen that want ad) to run around the city and pick peoples pockets. In reverse. What they did was drop little paper phones into peoples pockets and purses, alerting the unsuspecting punter to the ease with which a thief could grab their phone, and thus highlight the need for insuring it.
First person to point out this is very similar to the sneaky "umbrella drop" 2006 D&AD nominated campaign alerting young women to the ease with which people might spike their drinks from TBWALondon wins a cookie. Wait, that's me! Yeay, I win a cookie again. Gotta stop saying that, or I'll balloon by the next month.