First amendment. Freedom of speech/expression. I don't like the desecration of the flag. I have a massively negative response to it. However, it is at it's core a piece of cloth and abridging basic civil rights, even when one does something we find distasteful, is anathema to what the flag is meant to symbolize. Curtailing civil rights one at a time is a slippery slope. You may not like it, but if you really believe in our Constitution and the rights it affords us you must defend others' rights to do something that is personally distasteful, otherwise you give up your own freedoms, one right at a time.