FWIW I've had varying responses while travelling elsewhere in Europe on this topic which is why I thought I'd ask.

One place I thought I'd get static was at the Cafe Sacher in Vienna but the maître d' not only encouraged taking some photos, he volunteered to a picture of me. Now, it wasn't full at that moment and that might've played a role but it wasn't the reaction I was expecting and I was pleasantly surprised.

I'm not out to make waves being the genetically polite Canadian so will see how it feels in each venue as it will no doubt vary.