Well taking it at face value for a moment - and I have my reservations on that front - it is understandable that someone would be pissed off.
If a regular poster here started a thread saying 'another mum at my DD's school (who is also a governor of the school) has posted on a website things about my DD and is pretending to be someone that they aren't' then I think they would be told to 'tell the bloody woman what's what - or words to that effect!
However, I have met cod in RL, and thought that actually she was miles nicer in RL than on here - so I'm not falling for it really!