Not blackmail, but expect phishing attempts. They have your personal information and can now throw it into their large database which probably already had some information about your online interactions, making it easier to phish new targets. Remember these are the people who've hacked a massive amount of Amazon accounts to begin with. Basically, be very wary of password reset notifications and things like that for Paypal, bank account, email provider, Steam account, etc even if they say your name outright. Check any link before you click from that sort of email and double check the address where the message came from.