Since iOS 3.1, Mobile Safari features an anti-phishing filter. In order to be protected from phishing sites as much as possible, the filter’s database must be up-to-date. According to Apple, the database upgrades automatically while the user charges the iPhone (in order to protect battery life). To upgrade you have to: connect the iPhone to the AC adapter, launch Mobile Safari and lock the screen. Easy enough except that most users exit Safari before locking the screen in a regular use.