Mobile operator Three has admitted there was a security flaw in its website which meant during "a very unique set of circumstances" a customer's personal details could be viewed by a total stranger.
The issue was highlighted to TechRadar by a concerned Three customer who received a telephone call from a stranger at the other end of the country after his details appeared on their computer.
What happened was two people with the same name entered their details into the "register for updates" form on Three's website within 10 minutes of each other.
The site's cache stored the first person's data and then served it as auto-fill data to the second, including their name, email address and telephone number.
"An unusual situation"
A Three spokesperson told TechRadar: "We take safeguarding our customers' data very seriously and have thanked the customer for drawing this to our attention.
"This is an unusual situation that we have investigated thoroughly to ensure it won't happen again. We have apologised to the customer and resolved the issue." Three did offer compensation to the customers, but only after it was requested.
Have you witnessed any peculiar activity while using Three's website? Let us know in the comments below.