Currently they are stored for a limited amount of time to prevent abuse. Of course the data is not used for any other purpose than that. Bad actors could create endless fake accounts and would drain all those account tickets available.

If you have any suggestions how to work around this issue, which is not a paywall, let me know. I'am open for improvements to be made. I don't like the fact that I have to store the data myself...

One thing I consider for a week now is open it up for oauth provider like Google/Facebook/Twitter - but this could open gates for abuse as well...