I like such things but don't wear them either for the attention they bring. I have a sign in the garage that says we don't call 911 and a picture of a revolver my buddy gave me but don't put that in the window either.
Maybe I'm too timid but also don't want to tip my hand over such things either.
Should I see you somewhere wearing that shirt I'll certainly grin and maybe make a positive comment in your direction too.