I think it's more personal [opinion] thing rather than cultural. To me, "Mr. Stallman" would sound sarcastic. And don't forget that we're talking about celebrit

I think it's more personal [opinion] thing rather than cultural. To me, "Mr. Stallman" would sound sarcastic. And don't forget that we're talking about celebrities. Another example - if you've grown up on Beatles music, you'd say Paul and Ringo rather than Mr. McCartney or Mr. Starkey, right? And I'm pretty sure Paul and Ringo prefer the former one ;)