This feels kinda wrong, but I have to keep in mind that these people chose to give up these items.

From the TSA Blog (I cannot confirm if true)

When prohibited items come through the checkpoint, passengers are given options:

1) Take the item to the ticket counter and check it in your baggage or a box provided by the airport.

2) Many airports have a US Postal Service or other shipping services area where boxes, stamps and envelopes can be bought so you can ship your items home.

3) If there is somebody seeing you off, you can hand the prohibited item to them.

4) If your car is parked outside, you can take the item to your car.