[masswerk]

I'm a confessing user of em-dashes (or en-dashes in fonts that feature overly accentuated em-dashes). It's actually kind of hard to not use them, if you've ever worked with typography and know your dashes and hyphenations. —[sic!] Also, those dashes are conveniently accessible on a Mac keyboard. There may be some Win/PC bias in the em-dash giveaway theory.

[whstl]

A few writer friends even had a coffee mug with the alt+number combination for em-dash in Windows, given by a content marketing company. It was already very widespread in writing circles years ago. Developers keep forgetting they're in a massively isolated bubble.