I'm new to the Apple mobile world, have an Apple iPhone 4S with Verizon account, and am worried about security. For background, I'm an information systems engineer from a mostly Microsoft background and would never consider running any Microsoft device without firewall, intrusion detection, antivirus, etc. So far, I haven't been able to determine what provisions for security are delivered on the 4S (or Apple devices in general), what security applications may be available, and what if any can be applied without jailbreaking or rooting. Searches on the Internet for firewalls and antivirus are confusing, and a search on this form for firewall didn't turn up any posts. Any pointers would be appreciated.