Both times I've picked up 'offered' items, I've met the donor in the parking
lot of the local supermarket. The Barstow list warns against giving a
stranger your address, or even a phone number. Everything's done by email.
The exception was - which I forgot to mention before - a family who had a
choice between giving away 4 black kittens, or taking them to be put to
death. I
did go to their house, and gave them the fee required by the local no-kill
facility. I also made arrangements for them to get the rest of their cats
'fixed' at a discount so that the same dilemma wouldn't strike again.