I bought a used Android phone yesterday, which had a factory reset done. I tried to log in my Google account, but it required that the previous owner also provide their credentials to be able to proceed. Thankfully, he was helpful in that regard. Apparently you can't just log into a wiped phone that someone else has used. Is this a new security protocol? I can't find anything about it online.
If it is true, all those used phones at the pawn shop will be useless to the new owners, unless the previous owners have provided their Google usernames and passwords. Unlikely in my opinion.