During the account verification process, users must take a picture of a valid identification card and a picture of themselves holding that ID card.
In order for this system to work, we must collect information on the identification card that can identify a specific person (such as their name, country, etc.). We also store the two pictures taken.
No personal data is ever shared or sold. The only purpose for collecting this information is to have a functioning verification system.
So let's say a user tries to verify their account with a government issued ID card and the next month they try to acquire a 2nd verified account but this time by using their driver's license.. They wont be able to acquire a 2nd verified account because our system will pick it up. (same name, same country, etc.)
Of course its possible to have two identical names living in the same state/country and this is why we also need to store the pictures to make sure that they're not the same person.
We also collect the device id and if a user tries to verify multiple accounts on the same device, our system will pick it up and we'll need to dig deeper to see if it's really the same person trying to acquire two accounts or not.
It goes much deeper than this but I hope this briefly explained the process.
Of course, there's never going to be a perfect verification system but at the very least what we're doing adds an extra layer to avoid voting manipulation on our platform.
Twitter for example.. they charge $8/month and all you have to provide is a phone number..