> changing this behavior will break many sites. slack, discourse, Gmail chat/Hangouts , Facebook messenger, and I'm guessing discord etc.

How will it break any of those sites?

If you mean that it won't copy-and-paste formatting, which is encoded in a mark-down like syntax, then that's true - but most of the time when I copy something on a website, the formatting there rarely makes it through to another application (like any of the ones you mentioned) anyway, and most of the time when it _does_ survive the journey, I silently curse and try to remember what the "paste without formatting" hotkey is.

since HN doesn't allow emoji I can't post an example. without this feature what you copy in slack would be

    text <img src="happy.png"> text

instead of

    text (@) text

where (@) is actual utf8 emoji

same for vscode/Monaco where the editor adds a clickable color box for css colors.

It'd be nice if browsers would copy an image's alt-attribute if you tried to copy some text that included an image; that would solve the problem.

In any case, I would gladly give up the ability to copy-and-paste an emoji if it meant never again seeing a long line trying to link me to some website just because I had the audacity to copy three words from a news article.

> changing this behavior will break many sites.

Okay, add an opt-in?

Letting the selection get hijacked on the way to the system clipboard silently is bogus.