Suggestion: pause data stream on page blur

[brentax]

If a user selects a different browser tab or minimizes the browser, there's no point in continuing to send that client data until the page is focused again.

[ericlaw1979]

Yeah, I think the Page Visibility API is the simple/cheap fix here: mroth/emojitracker#43. You could probably pause DOM updates immediately, then after some period (60s?) have the client disconnect the stream until/unless the page becomes active again.