On Tuesday, I woke up to sites down and my login not working. No emails from Heroku. After emailing support, I got an automated response that I'd been banned for violations of the Acceptable Use Policy. No details, just instantly dropped.
I've sent 10s of emails to every Heroku and Salesforce support and security department, called the SF offices, and tried social media. I still have no idea why my account was suspended, and apparently I have no recourse to get my company data back (backups, credentials...everything is through the Heroku login).
Heroku is trying to put me out of business, I recommend you leave them before they do the same to you!