From via Securing Mobile Devices May Be an Impossible Task:
Attacks against smartphones such as BlackBerrys, iPhones and Android phones have become quite prevalent in recent years and many of them have focused on getting malicious apps on users phones. Thats a quick and easy way to get access to user data and sensitive information. But there are a slew of other real and potential vectors that attackers have at their disposal no, as well. Going after the device firmware is one potential method, as is attacking the mobile infrastructure itself."
If I can update your phone remotely, I own the phone at every level and I own you. Its game over," said Don Bailey, a senior security consultant at iSEC Partners, said during the panel discussion.
While I myself have been thinking about mobile security, this is an angle I didn't even consider. If hackers can pwn the mobile phone network itself, well, everyone's mobile device is in danger. There's not much you can do about it, either.