Context collapse
Etymology
The term was developed by researchers of social media around 2010–2011, notably danah boyd and Alice Marwick, to describe how networked platforms merge audiences that offline life keeps apart. "Context" is the social setting that tells us how to behave; "collapse" is the loss of the walls between settings. It named a problem that predates the internet but became unavoidable with it.
noun phrase · /KON-tekst kuh-LAPS/
What happens when a single post reaches many different audiences at once, flattening the separate contexts you would normally speak to differently.
What it names
It explains the peculiar strain of posting online: your boss, your grandmother, and your closest friends are all reading the same words meant, really, for none of them.
Example
She deleted the joke after realizing context collapse meant her coworkers and her college friends would read it in completely different registers.
Related idea
Context collapse is the audience-merging problem; code-switching is one response to it — shifting how you speak for different groups, which becomes impossible when the groups are fused into one feed.