A jailbreak for the iPhone 4 has been engineered and released by hackers, meaning that dodgy users can gain access to all kinds of unofficial content.
The jailbreak comes courtesy of the 'iPhone Dev Team', which has offered similar firmware hacks in the past.
This time the jailbreak works simply through the Safari browser from an iPhone.
All shady users need do is head on the relevant website on their phones, start the process and the gates are open to a flood of non-Apple approved software and use on other networks.
It sounds really naughty but the process is now legal in the US and so is likely to be considered above board in the territory.