Guy using his metal detector at a playground to collect small pieces of metal that could

Probably injure a kid if they fell on it. But that’s a guess.

Make him a billionaire

Haha, I found it from reddit: "Guy using his metal detector at a playground to collect small pieces of metal that could be harmful to children. (He makes a few dollars in coins on the way but showed us he mostly finds junk he picks up for their safety)"