Mechanisms for blocking repeat voting
These are the main mechanisms we offer to block repeat voting:
1) Blocking repeat voting using the browser - this method is not very strong, as users can delete the browser "memory" to circumvent this mechanism.
2) Blocking repeat voting using IP addresses - this method is much stronger and more than enough for most of the cases, however, a more sophisticated hacker can overcome this by writing a bot that switches IP's automatically - not trivial, but possible.
In addition, from the results dashboard, you can export all the vote submissions to verify there aren't any cheat patterns (e.g. irregular submission times, bursts of votes to a specific side, etc.).
How To add IP vote blocking
1) Edit your poll
2) In the Block repeat voting drop-down, select Block based on browser & IP
Other recommendations
In high-profile voting scenarios where voters are motivated to cheat, we recommend not showing users the results before the voting ends. When users see the results, they are more prone to try to "hack" the poll.
Only registered users
To ensure that only registered users can vote and to prevent multiple votes from the same user, the most effective approach is to embed the quiz, poll, or survey on a website section that requires users to log in. This way, access is restricted to registered users only, and voting is tied to their unique accounts.