The Bureau has noted an increase in the number of Vishing attacks, where the customers are sent a phishing email or text asking them to contact a fake bank phone number and give up their personal banking details - which can include your credit/debit card details.
The FBI Internet Crime Complaint center described one particular instance of a vishing attack: "On calling the telephone number, the recipient is greeted with 'Welcome to the bank of ...' and [is] requested to enter their card number in order to resolve a 'pending security issue',"
The popularity, availability, relative anonymity and low cost of VoIP services mean that Voice over IP has become the preferred vector for Vishing attacks.
VoIP callers are not required to give their Caller ID information until now and creating a VoIP account - at least in the UK - does not require a registered landline.
Arstechnica speculates that the callers themselves might not be aware of the nature of the business if the whole process had been outsourced to a foreign country.