Oh, it happens here: https://github.com/tofumatt/around/blob/2d6719d2786d53c73bbb04a0dc98cdb99698debd/www/js/views/checkins.coffee#L219

It's so the AJAX search that searches-while-you-type doesn't fire off a bunch of requests AND wait for them to complete. If you type "testing" it will cancel requests as you type for "te", "tes", etc.