Seems to be a recurring theme lately.
I and a few other guys on here have had similarly worded threats in the last few months.
I can't imagine that she could afford the legal bill which could run into many thousands I would think.
It's one thing to call someone a twat which could conceivably come under libel, deformation laws etc, however, if you say that someone's service was poor then it's a whole different ball game. It's largely one person's word against the other's. Does this now mean that any restaurant critic who gives a bad review will be prosecuted, or what about the millions of poor reviews on Trip Advisor of hotels, restaurants etc etc.
I dare say that prossies that are considering taking action are just hoping that the threat of outing a punter will be sufficient to get what they want.