I just deleted over 2k fake customer accounts

[Lychee88]

I removed the create an account option via the customer account log in and that didn't work, so I removed the customer account option from my header and they STILL keep creating fake customer accounts. Not sure how they're getting in but every single day I'm getting fake accounts. Also not sure why they're bothering to create fake accounts and how is it benefitting them by doing so. 

Any clue to how they're creating accounts without the create account log in link?

[Lychee88]

Another one was created as I was writing this post. They all have Russian emails. I'm getting hit every couple minutes.