Mostly, I tell people when the symbol of their nation that they are flying with apparent pride looks ready for the old flag's home (the fire). The portion of the U.S. Code pertaining to the flag states: "The flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning."
I like to point out that regulation, point at their flag, and ask if it is still "a fitting emblem for display," considering that it is flying there as a symbol for our country.
For example, my daughter takes lessons at a cheap little tennis club. On one visit I saw that there flag was faded, tattered and slightly tangled in a tree. I pointed that out to the person in charge. The next time we visited, I was impressed to see a bright, new flag flying free of encumberance.
I voted early on Halloween. I couldn't help but notice that the U.S. flag flying at the St. Louis County Board of Elections - as citizens were casting votes for the next president - was faded and frayed. It is clearly not "a fitting emblem for display." I pointed this out to the young guy working security. He said he didn't work there, he worked for the County.
Once I got inside the building, I pointed it out to somebody who did work there. It even said so right there on his sweater. He looked at me like he had 100 things to do and I was now 101. He said, "I'll see if we have another one," but then obviously did no such thing.
I think I'll stop by Monday and see if he found "another one." It's only the symbol of our country, after all, and it's only flying at a federal facility responsible for monitoring the process that empowers us to choose the next president of our country. Why shouldn't it be a little faded and frayed?