I was, about a year ago I name changed, put up a post regarding a situation I was going through with my best friend at the time, it was very specific and I included exact texts that were sent back and forth (stupid in hindsight).
A couple days later she came round to my house, she looked very upset, I invited her in and she said 'Well I've seen your mumsnet post'. She was really hurt about what was written, I was really upset that she had went searching for the post (she knew I was being off with her so searched mumsnet knowing I use AIBU a lot). We ended our friendship that day.
We made up a few weeks later and laugh about it now but boy have I learnt my lesson. She showed her husband and her mum and her sister what I wrote and I was so embarrassed seeing them again. But luckily it got all our issues out on the table and we are better than ever.
Anyone else been outed on mumsnet?