Clappers Response - Janie

I think that the point of making the identity of the clappers unknown until the end was to keep readers interested. Neal Shusterman didn't want his readers to understand what was really going on with the clappers until they were actually revealed, which is why they were cleverly inserted into the book early on:

   "'Start clapping!'
   'What?'
   'Start clapping. Trust me!'
   A single nod from Connor makes it clear that he gets it, and he begins bringing his hands together, slowly at first, then more and more quickly. She does the same, both of them applauding as if they were at a concert cheering for their favorite band.
   And beside them, a student drops his backpack and stares at them in utter horror.
   'Clappers!' he screams
   In an instant, the word is out.
   ClappersClappersClappers . . .
  It echoes in the kids around them. In an instant it reaches critical mass, and the entire crowd is in full-blown panic." (88)

And then a few pages later, Shusterman actually explains what a clapper is, but not in clear detail.

"The threat of clappers is so effective because no one really knows what they stand for." (90)

   "The old woman looks at them suspiciously. 'Does this have anything to do with that fiasco over at the high school? Are you clappers?'
   'Do we look like clappers to you?' says Connor.
   The woman narrows her eyes at him. 'Nobody looks like a clapper.'
   Connor narrows his gaze to match hers, then goes over to the wall. He holds up his hand an jabs it forward with all his might, punching the wall hard enough to bruise his knuckles. A little painting of a fruit bowl falls off the wall. Connor catches it before it hits the ground and sets it on the counter.
   'See?' He says. 'My blood isn't explosive. If I was a clapper, this whole shop would be gone.'" (92)

The key phrase being "My blood isn't explosive", this shows that Shusterman does tell his reader what a clapper is, but I think he could have done a better job of it. I was really confused as well until Mai and Blaine are in position to detonate themselves.

Lev does become a clapper for a reason, though, and on page 229, when Lev has his first meeting with Cleaver, Mai, and Blaine:

   "'How much do you hate [the people that were going to unwind you]?' Cleaver asks again.
   'Totally and completely.'
   'And how much do youi want to make them, and everyone else in the world, pay?'
   'Totally and completely.' Someone has to pay for the unfairness of it all. Everyone has to pay. He'll make them."

You see, Lev had almost been hardened by all he had been through after he left Connor and Risa. He recognized the unfairness of it all, not in just Unwinding itself, but in how angry it makes him, and how his parents actually made him want to be unwound.