Things you cannot say without raising security concerns...

Last month a Hollywood producer was detained for several hours for
honestly answering a TSA screeners question as to his purpose for
visiting. The answer to the question: "I'm here to shoot a pilot."

Yesterday, a single engine GA pilot was intercepted, forced to land and
was greeted by 20 federal agents. As he was overflying a military base,
he was communicating with the controllers. When queried as to his
destination, he responded that he could not disclose that information
because he was employed in a hostile work environment and that
disclosing the location could give his employers competition a business
advantage. It seems the controller only heard the word "hostile" and
immediately notified the security apparatus.

Be careful what you say and to whom you say it, it is likely to be
interpreted out of context.