Hand-written, you say? Hmm. Depending on the circumstances I'd have certainly made some noise about it. Like, gone up to someone "in charge" -- cuz, you know how fond some are of instituting ad hoc regulations -- and let them know that sentiment is offensive and that it probably violates "rules." Remember, you're not obligated to them those rules are.

Or like boca, simply ripped the stupid thing down out of disgust and walked away. Let 'em detain me. I'm willing to give up a little temporary comfort to crumble this security cookie.

"God Bless [the] TSA," I ask you!