To log into an AT&T GoPhone account, all that is required is the phone number and a 4 digit PIN. 4 digits? That's absurdly weak. If someone wanted to prank me and knew my phone number, it would be easy to get into my account, change billing settings, sign up for all sorts of "feature" packages, and who knows what else. Are prepaid accounts generally secured this weakly? I googled around and saw that some Verizon prepaid users had their accounts hijacked (4-digit "security code" guessed by hacker when talking to Customer Service), and their phone service re-directed to another mobile phone. The hacker would then use their minutes. Is there any prepaid carrier that takes security more seriously?