In thinking back to my copyright law course I believe we are dealing with "intellectual property" issues here as opposed to "real property". For instance, if the State of FL purchases school textbooks and they become the property of the schools, the people of the state do not have a right to photocopy the information (intellectual property) in that book or distribute it without proper remuneration or permission from the creator of that material.
Likewise, I am part of the state, but I cannot cut down a traffic signal (real property) and put it over the bar in my den because it would look cool. Nor can I go sleep in the county jail (real property) for a night just because Mrs. dg threw me out for spending too much time on Sowal.
Certainly the people are the state as you point out, but the state's (and our) interests are in mind when use of certain properties is limited.
I hope that helps.![]()
I took intellectually property courses at a law school when the internet was really taking off....now I am aging myself...

But, I digress..... Intellectual Property is something created, like a web shopping cart program or logos that promote a business or country, etc; and are used to derive income. If the educational or warning sign was used to derive income by the Designer, that is a different issue. I do not think that the State has a copyright on colored flags or intended to derive income. If that were the case, every beach in the US who used a similar colored flag to warn beachgoers would in violation of the copyright, if there is indeed one. Everyone in the world who used the universal red flag color would be in violation, also.
Now, if they had hired an artist to draw a shark or jellyfish flag and the intent was to create a sense of community nationally via the flag system, that would be different, but colors...no, don't think so.
Your example of stealing a State owned stop sign is theft, not copyright infringement. The same goes for textbooks. The author has sold the books for profit to the School and copying them would be considered plagiarism.
The reason the attorneys told FG that no one has asked is probably due to the above reasons... which really are just common sense. If that were not the case, anyone who wanted to use the color red to denote danger would have to call the State of Fl.
