Three months after trying to withdraw money from a Canadian cryptocurrency bank called Einstein Exchange, Reddit user LezzBeFriendz received a terse message: Stop emailing or we’ll suspend your account.

“As you have been told several times by several of my team members, by constantly emailing in you are further slowing down our processing times and causing further delays in your withdrawals,” read the Oct. 15 message from Einstein Exchange.

“Please stop continuously emailing in, it is adding to our backlog. We will email you with any updates or when your pending withdrawals have been processed. Please be aware that constantly contacting support via chat and email will result in your account being disabled/blocked on our platform.”

The message was a red flag for Einstein Exchange’s customers—and it turns out that law-enforcement had some concerns, too.

Einstein Exchange billed itself as a trustworthy alternative to other cryptocurrency exchanges, where customers lost millions to various scams and hacks. But now Canadian authorities have accused the bank of vanishing with $16 million in investors’ money and locking their offices. 

Cryptocurrency, a form of digital money, works without centralized banks. The system can be a perk and curse. Although cryptocurrency is harder to trace and more volatile than traditional currency (sometimes leading to huge gains for investors), it can also be a pain for everyday investors to buy and trade. To streamline the process, an industry of cryptocurrency trading companies have offered bank-like services, where customers can theoretically deposit and withdraw their digital money.