Yes, they do it wrong because (1) they don't know better and (2) they let their software convert lower case text into upper case (a feature nearly every typographic software provides).
Yet, if we let the majority of illiterate people decide what's right and what's wrong we could as easily decide to have 2 + 2 = 5. Here's an official text of the correct today's rules on how to write a capital "ß" (it's in German): http://www.duden.de/sprachwissen/rechtschreibregeln/doppel-s-und-scharfes-s
