There is no law against using all caps with Brush Script, Old English, or El Grecko because I see it done in every city I have ever visited. A couple of years ago I made 50 banners for a reverend from Nigeria and they loved my design. I got $1200 each for these 3'X6' banners.
But you had to refund the good reverend $1,100 of it each for the shipping costs that he prepaid to another party........ LOL
I never thought a soul on this planet would be duped by one of these scams, but back when my wife and I owned a Bed and Breakfast, I actually met a fellow B&B owner at a trade show who had fallen for it and it cost her a couple thousand bucks.
Working as a 911 Dispatcher last year before buying my current sign company, my former town was besieged by a scam artist who would call people while posing as a well known detective claiming that they were about to be served a warrant to appear before a grand jury and he could make it go away for x amount of money. It could only be paid with a prepaid Debit card and I'm not kidding, dozens and dozens of people fell for it.
There may not be a law against using all caps with those fonts, but you and I know that there SHOULD be a law against it.