There's an alarming rumor circulating that suggests that UK network O2 forwards your cellphone number to any website you visit with your smartphone. Lewis Peckover built a webpage that displays your header data, finding a field called "x-up-calling-line-id" which was his own phone number. Angry users have already flooded O2's Twitter, which is currently issuing the response: "Security is our top most priority, we're investigating this at the moment & will come back with more info as soon as we can" The Next Web confirmed that Orange, T-Mobile and Vodafone do not send numbers, but GiffGaff (an O2-owned MVNO) does. TNW's sources say that it's most likely an internal testing setup that has been acci
