Cellular operator 3 Italia has been ordered to stop billing some of its data customers while an investigation is carried out by competition regulators. The firm is under scrutiny after some subscribers were faced with bills of up to EUR10,000. Regulators are studying whether customers are being made fully aware of the data limits imposed on their accounts and the costs associated with using data services while abroad. The investigation relates to the period 21 September 2007 to 31 May 2008, Telecompaper reports. 3 Italia says it plans to launch a campaign to educate customers on its charges for data services.