Google says it's fixed a Wallet security flaw that potentially allowed a phone thief to spend a user's prepaid balance. The ability to provision new prepaid cards had been suspended pending the update, but has now been restored. Things aren't quite back to normal in the Big G's world of mobile money, however. Users still find themselves caught between two competing arguments over an entirely different vulnerability, which involves a 'brute-force' attack on rooted devices. Google insists that this isn't a major concern, so long as Wallet users refrain from rooting, and that the system still "offers advantages over the plastic cards and folded wallets in use today." On the other hand, the company that discovered this issue -- zvelo -- has come back at Google with an equally blunt response. It acknowledges that a handset must be rooted to be vulnerable, but crucially its researchers also say that a device doesn't have to be rooted before it's stolen. In other words, they allege that a savvy thief can potentially steal a phone and then root it themselves, and they won't be happy with Wallet until it requires longer PIN number. Whichever argument sways you, it's worth bearing in mind that there's no evidence that anyone has yet managed to exploit these weaknesses for criminal purposes.