How would you feel if:
Your postman opened and read all your mail?
A telephone operator listened in on all your calls?
Well, Facebook DOES that! And they are proud of it!
If you message someone with a catch phrase such as:
"are you OK?"
"what's the matter?"
"I've had enough!"
Then they might report you.. or at least use that excuse to analyze all your messages (wink wink).