Why can't cybercriminals do without customer service?

Imagine this: you boot up your laptop and see that hackers have struck and are demanding a ransom. That's not all, they've left a customer service phone number. This sounds crazy, but to make chunky money, cybercriminals can't do without this helpline. Cybercrime expert Rolf van Wegberg (TU Delft) explains why.

Source: University of the Netherlands