The various arguments and passions today concerning the Confederate flag are good examples of how emotionally-charged semiotics (the signs and symbols of communication) can be.
Flags are often used as examples of how simple signs can arouse strong feeling. The arguments about the Confederate flag are arguments about how to define a symbol, which of its many possible meanings is the one.
A more important point to be made here is that each of us has a myriad of semiotic symbols in our minds and emotions can be touched off by any of them at any time.
If you don’t know ho to communicate about these kinds of explosive symbols/signs—many of which are idiosyncratic—you will have problems, some of which will get defined as “psychological” when they are not.
It is beneficial for Buddhists (and others) to contemplate the emptiness of semiotics like the Confederate flag and then apply this understanding to how we think, perceive, feel, and communicate about other signs.
Edit: Concerning the flag, notice that the community (whichever one) is forced to come to some sort of “decision” about the flag’s meaning. This is so because the flag has to mean something since it is a prominent public sign/symbol. The “community” can’t avoid ascribing some meaning to it. Notice also that that is what Obama and many others have been doing, ascribing meaning to the flag. This is how elites (and the media that highlights or ignores them) influence culture, by influencing how we react to symbols and what those symbols are and/or mean. Disputes over semiotic meaning are very common in both the public and private spheres.
Edit 2: Just because the community is forced to give the flag meaning doesn’t mean it will give it the right meaning. And it also doesn’t mean that any of the widely available meanings are right.