It was only an email for goodness sake. An email address does not contain a home address. It seems to me that some people need to lighten up a bit.
The most sensible response as suggested earlier , would be to say thank you , but no thank you and be careful of contacting passengers who may not like it etc etc.
I wonder if those sour grapes type people who insist on contacting the airline would still feel this way if a) it really did happen to them and 2) they liked the FA!
Worry about the big stuff in life, not overdramatise the small stuff