The site reports that its own reporter was "hit with charges... immediately after switching his phone from airplane mode to normal mode."
We suspect user error may be the problem in this case, but it's not easy to switch data roaming on accidentally. Data roaming is turned off by default on iPhones, and you have to wade a couple of levels into the settings menu to turn it on again.
O2, which is the network used by most iPhones in the UK, says it's "investigating these reports with Apple," but it won't confirm there's a problem with the phone.
There's a precedent for the iPhone going AWOL (airtime without leave) abroad. Last August, Apple released a software update to fix a bug that caused the iPhone to connect to the data network when sending an MMS, even when roaming.
We're waiting for a comment from Apple on the kerfuffle, but in the meantime, let us know in the comments if you've seen any freaky charges after your summer forays abroad. And if you do have unexpected bills, we suggest you contact your network and insist on a refund.