O2 warn against error that means strangers can hear your calls
If you're a customer with O2, it might be a good idea to not talk about anything too sensitive on your phone after a problem that meant strangers were able to listen in on your calls.
'Crossed lines' meant that third parties have been connected to various calls, while not being heard themselves.
"While on the surface this may seem a minor inconvenience, there is a risk of having your private or financial information overheard and suffering a loss on the back of it," said MoneySavingExpert.com githamper Martin Lewis.
"Until O2 sorts itself out, the sensible precaution would be to think carefully what you say if you're speaking to someone via the O2 mobile phone network."
O2 say that they fixed the problem on Tuesday and that there had been no further complaints about people being able to hear conversations, silently. Like anyone would know there was something to complain about in the first place.