At this point, nothing. If/when that proves to be a problem (probably sooner rather than later if the idea/site proves popular), then my initial plan is to verify emails, require unique emails on registration (obviously), and keep email addresses of deleted accounts on file for a short amount of time.
That would keep someone from deleting an account and immediately recreating it with the same email, so the person would instead have to use a different valid address per account, which probably is more trouble than it's worth to just participate in the site (at least doing that would be kind of fun).
Any thoughts on that? Your idea of mobile number verification is also an option, although it's a little too extreme for me to try unless things get bad.
That would keep someone from deleting an account and immediately recreating it with the same email, so the person would instead have to use a different valid address per account, which probably is more trouble than it's worth to just participate in the site (at least doing that would be kind of fun).
Any thoughts on that? Your idea of mobile number verification is also an option, although it's a little too extreme for me to try unless things get bad.