disallow registration based on birthday

[INK3S]

we are running 3.7.1 & still getting alot of spambot registrations, all using the same birthday. is there a way to disallow registration based on birthday, or possibly ban/moderate based on birthday? any ideas would be appreciated!

edit: we have the birthday field hidden during registration, and it is not a required field, so maybe disallowing registration based on hidden fields filled out at that time would be the way to go.

[Steeler Nation]

I could use some help with this too. Getting a ton of spam registrations, all with the birthday of January 1, 1980.

It's easy enough to search them, but you have to do individual deletes, which can take a LOT of time. I need a mass prune script.