Massive outage at O2 affects 32 million customers December 6, 2018 https://www.theinquirer.net/inquirer/news/3067743/o2-outage
Why millions of Brits' mobile phones were knackered on Thursday: An expired Ericsson software certificate December 6, 2018 https://www.theregister.co.uk/2018/12/06/ericsson_o2_telefonica_uk_outage/