Spam on Twitter

I have an account on Twitter, although to be honest, I don't use it much. Lately, I've started receiving e-mails by Twitter that notify me that user mpla mpla mpla is following me on Twitter. I click on the user's profile and I discover hot women that want to have sex with me, etc. You get the point. I block these users without any further delay. I am wondering. Is this a new kind of spam?