Vodafone, Orange and T-Mobile have been heavily criticised in a Home Affairs Committee report for failing to notify customers that their phones could have been hacked by journalists at News International.
The Unauthorised tapping into or hacking of mobile communications document argues that a failure in communication between police and operators meant that customers were not informed that they may have been hacked until two years after the man responsible, Glen Mulcaire, was sent to prison.
"It seems impossible now to discover what went wrong in 2006. Some of the mobile companies blamed police inaction. Vodafone and Orange UK/T-Mobile UK said that the police had not told them to contact their customers until November 2010," the report said.
"[Acting Metropolitan Police deputy commissioner John] Yates accepted that some of the correspondence between the police and the companies had not been followed up properly."
Despite these errors by the police, the mobile operators came in for stinging criticism. Only O2 emerged from the event with any credit, having proactively attempted to inform its customers.
"The companies cannot escape criticism completely. Neither Vodafone nor Orange UK/T-Mobile UK showed the initiative of O2 in asking the police whether such contact would interfere with investigations," the report said.
"Vodafone at least sent out reminders about security, (Orange UK/T-Mobile UK may not even have done that). They tightened their procedures, but they made no effort to contact the customers affected."
The report also touched on the new mandatory data breach rules for telecoms firms, claiming that it is a necessary step to improve privacy for customers.
"We welcome the measures taken so far to increase the security of mobile communications. However, with hackers constantly developing new techniques and approaches, companies must remain alert," the report said.
"We would like to see security advice given as great a prominence as information about new and special features when customers purchase new mobile communication devices."
The phone hacking scandal has engulfed the UK's media, technology and political establishments in the past two weeks, with The Sun hacked by LulzSec and the FBI probing Murdoch's News Corporation for alleged 9/11 phone hacking.
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