It's then put on YouTube, where lots of people view it, and they prankster makes money at the victims' expense. The victims, of course get no money.
Often, the pranks involve stealing from the victims (The items are given back) or threatening to hit them. It's mean and cruel and stupid and I hope the fad ends soon.
Having said that, some prank videos are actually positive and I'm fine with those
For instance, I did see one video that's going viral in which a fake parking meter reader gives tickets to motorists who don't know the meter reader is just an actor.
The motorists get annoyed, until they open the envelope to read their ticket. It's simple, but charming.