Free version allowing multiple voting

Hi,

Each time I have used the free version of the plugin until recently, my voters have only been able to place a single vote (NOT vote multiple times).

Now, after logging out of my website and logging back in again the next day it is allowing my users to place another (second, third, etc.) vote in each consecutive day.

Why is this happening as it hasn’t happened on the previous polls I ran. We use this for our Student President election polling and I now have a student ‘questioning the reputation’ of our whole Student Voice process.

An answer as to why this has changed would be much appreciated.