With cookie-based voting, a timestamp is used to identify unique votes while the poll's id is set in the cookie to limit votes for a limited time. If it is important to identify users by ID or IP, switch to normal voting mode which will use your Voting API settings to record votes.

Visitor	Date	Choice
1483215014	Sat, 12/31/2016 - 3:10pm	"Fever" by Vybz Kartel
1483215413	Sat, 12/31/2016 - 3:16pm	"Fever" by Vybz Kartel
1483251565	Sun, 01/01/2017 - 1:19am	"Fever" by Vybz Kartel