Perfectly safe, mate. As is online shopping. And a damn sight safer than doing it by phone. You're telling your details to some **** you don't know. You probably also don't think anything of a waiter disappearing for five minutes with your debit/credit card when settling a restaurant bill.
PS, the card reader generates a unique key used to encrypt each data packet sent between you and the bank. Hugely difficult to break, not impossible, but it would take a computer hacker several years to decode even one packet into something meaningful let alone all the packets that comprise a request from you to the bank (for example the request that displays your current bank balance) So, dinny worry.
