An alarming story has emerged over the last 24 hours for mobile phone customers on the O2 network (potentially including MVNOs GiffGaff and Tesco Mobile that piggy back on O2):
Check out this page to test this for yourself (make sure you turn off WiFi so that you’re definitely connected via your provider’s network). It’s not believed to impact Vodafone, Orange, T-mobile or 3 customers, and may be dependent on which APN you use for your data connection (e.g. pre-pay vs. contract customers).
[Update 2 at 7pm UK time: O2 apology and FAQ via their blog and Information Commissioner’s Office pursuing alleged data breach]