They are using various lists leaked onto the Dark Web (most certainly the 2014 Ebay hack), asking for people directly when they call, and trying to phish for more information so they can clone identities and commit theft and fraud. So be very careful. Call from this number are often more sinister and personable than many scam calls you receive. Reported them to the National Crime Agency who seem to have several active investigations into them and are liaising with other agencies. Was told th